Diels-Alder adducts of medium-ring carbocyclic dienes prepared by rearrangement of catalytically generated cyclic oxonium ylides

The novel bicyclic and tricyclic systems di­methyl (4aS*,6S*)-6-methoxy-7-oxo-4a,5,6,7,8,9-hexa­hydro-2H-benzo­cyclo­hept­ene-3,4-di­carboxyl­ate, C₁₆H₂₀O₆, (I), di­methyl (4aS*,6R*)-6-methoxy-7-oxo-4a,5,6,7,8,9-hexa­hydro-2H-benzo­cyclo­hept­ene-3,4-di­carboxyl­ate, C₁₆H₂₀O₆, (II), (3aS*,9R*,10aS*,10bR*)-9-methoxy-2-oxa-1,3a,4,6,7,8,9,10,10a,10b-deca­hydro-3H-cyclo­hepta­[e]­indene-1,3,8-trione, C₁₄H₁₆O₅, (III), and (1S*,2R*,9S*,10aR*)-9-methoxy-8-oxo-1,2,3,5,6,7,8,9,10,10a-deca­hydrobenzo­cyclo­octene-1,2-di­carboxyl­ic acid, C₁₅H₂₀O₆, (IV), have been crystallographically characterized, allowing the determination of the relative configuration of the stereogenic centres. The poor quality of the di­carboxyl­ic acid crystals necessitated the use of synchrotron radiation.

S1. Comment

As part of a broad programme concerning the rapid construction of medium-ring polycyclic units found in natural products, we explored Diels-Alder reactions of vinyl-substituted cycloheptene and cyclooctene systems generated by formal [2,3] rearrangement of carbenoid-derived oxonium ylides. The novel bicyclic and tricyclic systems containing a seven-membered carbocycle, compounds (I), (II) and (III), were prepared by the reaction of dimethylacetylene dicarboxylate or maleic anhydride with 2-methoxy-5-vinyl-cyclohept-4-enone, itself prepared by [2,3]-sigmatropic ring-expansion of catalytically generated cyclic divinyl-substituted oxonium ylides (Scheme). Similarly, a bicyclic compound containing an eight-membered carbocycle, (IV), was prepared by reaction of maleic anhydride with 2-methoxy-5-vinyl-cyclooct-4-enone. \sch

Crystallographic characterization has been an effective method of unambiguously establishing the stereochemical outcome of these Diels-Alder reactions, permitting the relative configuration of the stereogenic centres in each diastereoisomer to be determined. Compounds (I) and (II) form a pair of diastereomers, in which the relative configuration at C8 and C9a has been determined as S*,S* and R*,S*, respectively. Aside from this difference in configuration, the other significant differences in molecular structure are in the orientation of the ester side arms attached at C1 and C2. These differences can be seen in Figs. 1 and 2 and are illustrated by the following interplanar angles, where plane A contains atoms C13/O13/C15/O14, plane B C10/O10/O11/C12 and plane C C13/C1/C2/C10: AB angles are 135.7 and 13.5°, AC 41.2 and 81.6°, and BC 130.7 and 86.5° for (I) and (II), respectively. Similarly, this is shown by the C2—C1—C13—O13 and O10—C10—C2—C1 torsion angles (Table 1). The different orientations have different intramolecular contact distances between the ester arms: the separation between O11 and O14 of 2.835 Å in (I), compared with 4.845 Å in (II), may be due to the formation of dimers in (I) through a weak C—H···O interaction between C4 and O13. In (II), where the two ester groups are almost orthogonal to one another, the closest contact is between O13 and C10 (2.65 Å).

The conformation of the two rings in this pair of structures is almost identical. In both cases, the six-membered ring adopts a nearly ideal boat conformation, with C3 and C9a displaced in the same direction from the plane of the remaining four atoms by 0.165 (2) and 0.205 (2) Å, respectively for (I), and by -0.203 (3) and -0.235 (3) Å, respectively, for (II). The overall ring plane has an r.m.s. deviation of 0.087 Å for (I) and 0.103 Å for (II). The planes through the two half-rings defined by C9a/C1/C2/C3 and C9a/C4a/C4/C3 have deviations of only 0.007 and 0.004 Å, respectively, in (I), and 0.002 and 0.006 Å, respectively, in (II), with a hinge angle about C9a···C3 of 16.79 (9)° in (I) and 19.79 (11)° in (II). The puckering parameters (Cremer & Pople, 1975) for both the six-membered and the irregular seven-membered rings are given in Table 1.

Adduct (III) is a tricyclic compound with four stereogenic centres, at C3a, C9, C10a and C10b, the configuration of which has been determined as S*, R*, S* and R*, respectively (Fig. 3). As in the previous compounds, the six-membered ring adopts a nearly ideal boat conformation, with C4 and C10a displaced in the same direction from the plane of the other four ring atoms by 0.515 (2) and 0.565 (2) Å, respectively. The overall ring plane has an r.m.s. deviation of 0.087 Å, while the planes through the two half-rings, defined by C4/C3A/C10b/C10a and C4/C5/C5a/C10a, have deviations of only 0.004 and 0.008 Å, respectively, with a hinge angle of 46.75 (7)° about C4···C10a. The five-membered ring is planar to within 0.009 Å, but with O1 and O3 displaced in opposite directions from the ring plane by 0.021 (2) and -0.042 (2) Å, respectively.

Compound (IV) is again a bicyclic compound, but in this case containing an eight-membered carbocycle and a six-membered ring (Fig. 4). In this case, the six-membered ring adopts an envelope conformation, with C1 displaced by -0.703 (7) Å from the plane of the other five atoms, which define a plane with an r.m.s. deviation of only 0.003 Å. The puckering parameters for the six-membered ring and the irregular seven-membered ring are given in Table 1. The hydrogen bonding links molecules to form centrosymmetric dimers by inversion through (0, 1, 1/2). These dimers are each linked to four neighbouring dimers related by 2₁ screw axis operations (Fig. 5). These interactions result in a two-dimensional network structure which is infinite in the bc plane but does not propagate along the a axis.

Related literature

For related literature, see: Clark et al. (2001); Cremer & Pople (1975); Sheldrick (1996).

S2. Experimental

The synthesis of (I), (II) and (III) has been described elsewhere (Clark et al., 2001). The Diels-Alder adducts (I) and (II) were each dissolved in the minimum quantity of warm diethyl ether; adducts (III) and (IV) were each dissolved in the minimum quantity of warm ethyl acetate. In each case, the solution was allowed to cool to room temperature and then hexane was added until slight turbidity was observed. The solutions of the Diels-Alder adducts were allowed to evaporate slowly at room temperature over several days to afford crystals suitable for X-ray analysis.

S3. Refinement

Due to very weak diffraction at high angles, data above θ = 26° for (IV) were excluded from the final cycles of refinement. In all cases, H atoms were placed geometrically, except for OH and Me, which were located from circular difference Fourier syntheses. Geometrically placed H atoms were refined riding on their carrier atoms, while those from the difference Fourier syntheses were refined as part of rigid groups allowed to rotate about the local C—O or C—C vector. The methine, methylene and methyl C—H distances were constrained to 1.00, 0.99 and 0.98 Å, respectively, and the O—H distance to 0.84 Å. H-atom displacement parameters were related to those of their carrier atoms by U_iso(H) = xU_eq(C,O), where x = 1.5 for OH and methyl H atoms, and 1.2 for all other CH. The Daresbury Laboratory SRS was the radiation source for compound (IV). SADABS (Sheldrick, 1996) was used to correct for the beam decay at the synchrotron.

Computing details

For all compounds, data collection: SMART (Bruker, 1999). Cell refinement: SAINT (Bruker, 2000) for (I), (II), (III); SAINT (Bruker, 1998) for (IV). For all compounds, data reduction: SAINT and SHELXTL (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL. Software used to prepare material for publication: SHELXTL for (I), (II), (III); SHELXL97 and PLATON (Spek, 2001) for (IV).

Figures

	Fig. 1. The molecular view of (I) showing the atom-numbering scheme and with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. The molecular view of (II) showing the atom-numbering scheme and with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as small spheres of arbitrary radii.
	Fig. 3. The molecular view of (III) showing the atom-numbering scheme and with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as small spheres of arbitrary radii.
	Fig. 4. The molecular view of (IV) showing the atom-numbering scheme and with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as small spheres of arbitrary radii.
	Fig. 5. A view showing the two-dimensional network structure of (IV). C atoms are drawn as open circles, O atoms as dotted circles and H atoms as smaller open circles.

(I) Dimethyl (4aS*,6S*)-6-methoxy-7-oxo-4a,5,6,7,8,9-hexahydro-2H- benzocycloheptene-3,4-dicarboxylate

Crystal data

C16H20O6	Z = 2
Mr = 308.32	F(000) = 328
Triclinic, P1	Dx = 1.320 Mg m^−3
a = 7.4878 (9) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.1793 (12) Å	Cell parameters from 5947 reflections
c = 11.0220 (13) Å	θ = 2.4–28.7°
α = 69.955 (2)°	µ = 0.10 mm^−1
β = 83.957 (2)°	T = 150 K
γ = 79.806 (2)°	Block, colourless
V = 775.85 (16) Å^3	0.5 × 0.3 × 0.3 mm

Data collection

Bruker SMART CCD area-detector diffractometer	3148 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.024
Graphite monochromator	θmax = 28.7°, θmin = 2.0°
ω scans	h = −9→9
9181 measured reflections	k = −13→13
3597 independent reflections	l = −14→14

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.035	Hydrogen site location: geometrically placed, Me from delta-F
wR(F^2) = 0.100	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.056P)^2 + 0.1526P] where P = (Fo^2 + 2Fc^2)/3
3597 reflections	(Δ/σ)max = 0.001
202 parameters	Δρmax = 0.34 e Å^−3
0 restraints	Δρmin = −0.20 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.65089 (14)	−0.13152 (10)	0.83490 (9)	0.0201 (2)
C2	0.80308 (14)	−0.14744 (11)	0.89538 (10)	0.0215 (2)
C3	0.94629 (15)	−0.05316 (12)	0.84004 (11)	0.0294 (2)
H3A	0.9429	0.0107	0.8910	0.035*
H3B	1.0674	−0.1123	0.8482	0.035*
C4a	0.77001 (14)	0.05129 (10)	0.63967 (10)	0.0207 (2)
C4	0.92117 (14)	0.03402 (11)	0.70076 (11)	0.0251 (2)
H4	1.0191	0.0798	0.6531	0.030*
C5	0.75280 (14)	0.13882 (11)	0.49805 (10)	0.0236 (2)
H5A	0.6749	0.0967	0.4588	0.028*
H5B	0.8745	0.1345	0.4535	0.028*
C6	0.67159 (14)	0.29555 (11)	0.47509 (10)	0.0255 (2)
H6A	0.7713	0.3500	0.4689	0.031*
H6B	0.6118	0.3342	0.3915	0.031*
O7	0.54631 (12)	0.39702 (8)	0.63726 (8)	0.0324 (2)
C7	0.53540 (14)	0.31555 (11)	0.58072 (10)	0.0229 (2)
C8	0.38436 (14)	0.22350 (11)	0.62452 (10)	0.0222 (2)
H8	0.2759	0.2789	0.6549	0.027*
C9	0.44706 (14)	0.09198 (11)	0.73858 (10)	0.0224 (2)
H9A	0.3417	0.0419	0.7752	0.027*
H9B	0.4853	0.1232	0.8063	0.027*
C9a	0.60482 (13)	−0.01491 (10)	0.70789 (9)	0.0194 (2)
H9	0.5589	−0.0578	0.6503	0.023*
O10	0.89137 (11)	−0.22613 (9)	1.11288 (7)	0.02906 (19)
C10	0.84307 (13)	−0.25517 (11)	1.02548 (10)	0.0215 (2)
O11	0.82751 (11)	−0.38646 (8)	1.03209 (7)	0.02792 (19)
C12	0.85284 (18)	−0.49222 (12)	1.15919 (11)	0.0332 (3)
H12A	0.9768	−0.4998	1.1846	0.050*
H12B	0.8331	−0.5839	1.1567	0.050*
H12C	0.7657	−0.4644	1.2221	0.050*
C13	0.50841 (14)	−0.22576 (11)	0.88904 (10)	0.0219 (2)
O13	0.43812 (13)	−0.27538 (10)	0.82533 (8)	0.0391 (2)
O14	0.46497 (11)	−0.24372 (9)	1.01364 (7)	0.02925 (19)
C15	0.34015 (17)	−0.34413 (15)	1.07634 (12)	0.0359 (3)
H15A	0.2379	−0.3259	1.0212	0.054*
H15B	0.2947	−0.3335	1.1597	0.054*
H15C	0.4037	−0.4406	1.0904	0.054*
O16	0.33115 (10)	0.18194 (8)	0.52459 (7)	0.02434 (17)
C17	0.22164 (16)	0.29506 (12)	0.43400 (11)	0.0300 (2)
H17A	0.1121	0.3275	0.4792	0.045*
H17B	0.1868	0.2617	0.3676	0.045*
H17C	0.2909	0.3735	0.3931	0.045*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0219 (5)	0.0182 (5)	0.0205 (5)	−0.0042 (4)	0.0006 (4)	−0.0065 (4)
C2	0.0225 (5)	0.0196 (5)	0.0215 (5)	−0.0038 (4)	−0.0006 (4)	−0.0053 (4)
C3	0.0246 (5)	0.0301 (6)	0.0298 (6)	−0.0106 (4)	−0.0068 (4)	−0.0006 (4)
C4a	0.0220 (5)	0.0175 (4)	0.0214 (5)	−0.0031 (4)	0.0020 (4)	−0.0057 (4)
C4	0.0227 (5)	0.0234 (5)	0.0267 (5)	−0.0074 (4)	0.0006 (4)	−0.0036 (4)
C5	0.0240 (5)	0.0249 (5)	0.0204 (5)	−0.0056 (4)	0.0018 (4)	−0.0057 (4)
C6	0.0250 (5)	0.0230 (5)	0.0252 (5)	−0.0073 (4)	−0.0004 (4)	−0.0024 (4)
O7	0.0501 (5)	0.0218 (4)	0.0270 (4)	−0.0074 (3)	−0.0083 (4)	−0.0073 (3)
C7	0.0279 (5)	0.0166 (5)	0.0213 (5)	−0.0021 (4)	−0.0060 (4)	−0.0019 (4)
C8	0.0222 (5)	0.0216 (5)	0.0218 (5)	−0.0013 (4)	0.0000 (4)	−0.0075 (4)
C9	0.0213 (5)	0.0221 (5)	0.0213 (5)	−0.0031 (4)	0.0017 (4)	−0.0049 (4)
C9a	0.0199 (5)	0.0189 (5)	0.0192 (4)	−0.0045 (4)	−0.0007 (4)	−0.0053 (4)
O10	0.0325 (4)	0.0313 (4)	0.0243 (4)	−0.0079 (3)	−0.0035 (3)	−0.0082 (3)
C10	0.0169 (4)	0.0231 (5)	0.0226 (5)	−0.0028 (4)	0.0004 (4)	−0.0057 (4)
O11	0.0372 (4)	0.0216 (4)	0.0229 (4)	−0.0053 (3)	−0.0029 (3)	−0.0037 (3)
C12	0.0443 (7)	0.0243 (5)	0.0246 (5)	−0.0063 (5)	−0.0020 (5)	0.0005 (4)
C13	0.0217 (5)	0.0205 (5)	0.0217 (5)	−0.0040 (4)	−0.0019 (4)	−0.0039 (4)
O13	0.0505 (5)	0.0475 (5)	0.0262 (4)	−0.0316 (4)	0.0005 (4)	−0.0095 (4)
O14	0.0284 (4)	0.0378 (5)	0.0230 (4)	−0.0147 (3)	0.0040 (3)	−0.0086 (3)
C15	0.0308 (6)	0.0475 (7)	0.0260 (6)	−0.0194 (5)	0.0027 (4)	−0.0025 (5)
O16	0.0248 (4)	0.0225 (4)	0.0256 (4)	−0.0024 (3)	−0.0052 (3)	−0.0073 (3)
C17	0.0275 (5)	0.0294 (6)	0.0301 (6)	−0.0022 (4)	−0.0082 (4)	−0.0051 (5)

Geometric parameters (Å, º)

C1—C2	1.3379 (15)	C8—H8	1.000
C1—C13	1.5001 (13)	C9—C9a	1.5514 (14)
C1—C9a	1.5184 (13)	C9—H9A	0.990
C2—C10	1.4982 (14)	C9—H9B	0.990
C2—C3	1.5060 (14)	C9a—H9	1.000
C3—C4	1.4992 (15)	O10—C10	1.2052 (13)
C3—H3A	0.990	C10—O11	1.3385 (13)
C3—H3B	0.990	O11—C12	1.4516 (13)
C4a—C4	1.3320 (15)	C12—H12A	0.980
C4a—C5	1.5150 (14)	C12—H12B	0.980
C4a—C9a	1.5170 (13)	C12—H12C	0.980
C4—H4	0.950	C13—O13	1.2002 (13)
C5—C6	1.5464 (15)	C13—O14	1.3342 (13)
C5—H5A	0.990	O14—C15	1.4538 (13)
C5—H5B	0.990	C15—H15A	0.980
C6—C7	1.5085 (15)	C15—H15B	0.980
C6—H6A	0.990	C15—H15C	0.980
C6—H6B	0.990	O16—C17	1.4301 (13)
O7—C7	1.2132 (13)	C17—H17A	0.980
C7—C8	1.5297 (14)	C17—H17B	0.980
C8—O16	1.4221 (12)	C17—H17C	0.980
C8—C9	1.5301 (14)
C2—C1—C13	122.60 (9)	C8—C9—C9a	116.03 (8)
C2—C1—C9a	123.21 (9)	C8—C9—H9A	108
C13—C1—C9a	114.18 (8)	C9a—C9—H9A	108
C1—C2—C10	123.55 (9)	C8—C9—H9B	108
C1—C2—C3	122.35 (9)	C9a—C9—H9B	108
C10—C2—C3	114.05 (9)	H9A—C9—H9B	107
C4—C3—C2	112.70 (9)	C4a—C9a—C1	111.93 (8)
C4—C3—H3A	109	C4a—C9a—C9	113.80 (8)
C2—C3—H3A	109	C1—C9a—C9	106.99 (8)
C4—C3—H3B	109	C4a—C9a—H9	108
C2—C3—H3B	109	C1—C9a—H9	108
H3A—C3—H3B	108	C9—C9a—H9	108
C4—C4a—C5	121.90 (9)	O10—C10—O11	123.98 (10)
C4—C4a—C9a	122.00 (9)	O10—C10—C2	122.84 (9)
C5—C4a—C9a	116.10 (9)	O11—C10—C2	113.12 (9)
C4a—C4—C3	124.04 (9)	C10—O11—C12	114.69 (8)
C4a—C4—H4	118	O11—C12—H12A	110
C3—C4—H4	118	O11—C12—H12B	110
C4a—C5—C6	113.52 (9)	H12A—C12—H12B	110
C4a—C5—H5A	109	O11—C12—H12C	110
C6—C5—H5A	109	H12A—C12—H12C	110
C4a—C5—H5B	109	H12B—C12—H12C	110
C6—C5—H5B	109	O13—C13—O14	124.22 (10)
H5A—C5—H5B	108	O13—C13—C1	123.17 (9)
C7—C6—C5	113.01 (8)	O14—C13—C1	112.57 (8)
C7—C6—H6A	109	C13—O14—C15	115.85 (9)
C5—C6—H6A	109	O14—C15—H15A	110
C7—C6—H6B	109	O14—C15—H15B	110
C5—C6—H6B	109	H15A—C15—H15B	110
H6A—C6—H6B	108	O14—C15—H15C	110
O7—C7—C6	122.44 (10)	H15A—C15—H15C	110
O7—C7—C8	118.34 (10)	H15B—C15—H15C	110
C6—C7—C8	119.10 (9)	C8—O16—C17	112.14 (8)
O16—C8—C7	113.30 (8)	O16—C17—H17A	110
O16—C8—C9	109.61 (8)	O16—C17—H17B	110
C7—C8—C9	109.19 (8)	H17A—C17—H17B	110
O16—C8—H8	108	O16—C17—H17C	110
C7—C8—H8	108	H17A—C17—H17C	110
C9—C8—H8	108	H17B—C17—H17C	110
C13—C1—C2—C10	−3.19 (16)	C4—C4a—C9a—C9	105.06 (11)
C9a—C1—C2—C10	175.18 (9)	C5—C4a—C9a—C9	−74.67 (11)
C13—C1—C2—C3	179.53 (10)	C2—C1—C9a—C4a	16.91 (13)
C9a—C1—C2—C3	−2.11 (16)	C13—C1—C9a—C4a	−164.60 (8)
C1—C2—C3—C4	−13.44 (16)	C2—C1—C9a—C9	−108.39 (11)
C10—C2—C3—C4	169.04 (9)	C13—C1—C9a—C9	70.10 (10)
C5—C4a—C4—C3	−179.04 (10)	C8—C9—C9a—C4a	52.83 (12)
C9a—C4a—C4—C3	1.25 (17)	C8—C9—C9a—C1	177.00 (8)
C2—C3—C4—C4a	13.99 (16)	C1—C2—C10—O10	−130.12 (11)
C4—C4a—C5—C6	−92.00 (12)	C3—C2—C10—O10	47.37 (14)
C9a—C4a—C5—C6	87.73 (11)	C1—C2—C10—O11	52.72 (13)
C4a—C5—C6—C7	−32.42 (12)	C3—C2—C10—O11	−129.80 (10)
C5—C6—C7—O7	127.29 (11)	O10—C10—O11—C12	6.96 (15)
C5—C6—C7—C8	−48.80 (12)	C2—C10—O11—C12	−175.91 (9)
O7—C7—C8—O16	153.63 (9)	C2—C1—C13—O13	−134.76 (12)
C6—C7—C8—O16	−30.12 (12)	C9a—C1—C13—O13	46.75 (14)
O7—C7—C8—C9	−83.90 (11)	C2—C1—C13—O14	47.41 (13)
C6—C7—C8—C9	92.34 (11)	C9a—C1—C13—O14	−131.09 (9)
O16—C8—C9—C9a	57.17 (11)	O13—C13—O14—C15	7.69 (16)
C7—C8—C9—C9a	−67.48 (11)	C1—C13—O14—C15	−174.50 (9)
C4—C4a—C9a—C1	−16.39 (14)	C7—C8—O16—C17	−75.50 (11)
C5—C4a—C9a—C1	163.88 (8)	C9—C8—O16—C17	162.26 (8)

(II) dimethyl (4aS*,6R*)-6-methoxy-7-oxo-4a,5,6,7,8,9-hexahydro-2H- benzocycloheptene-3,4-dicarboxylate

Crystal data

C16H20O6	F(000) = 1312
Mr = 308.32	Dx = 1.328 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 27.666 (9) Å	Cell parameters from 885 reflections
b = 5.066 (2) Å	θ = 3.1–18.1°
c = 22.793 (7) Å	µ = 0.10 mm^−1
β = 105.149 (5)°	T = 150 K
V = 3084 (2) Å^3	Block from hexagonal plate, colourless
Z = 8	0.50 × 0.45 × 0.25 mm

Data collection

Bruker SMART CCD area-detector diffractometer	2967 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.058
Graphite monochromator	θmax = 28.7°, θmin = 1.9°
ω scans	h = −37→35
10535 measured reflections	k = −4→6
3584 independent reflections	l = −27→29

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.126	H-atom parameters constrained
S = 0.98	w = 1/[σ^2(Fo^2) + (0.0412P)^2 + 8.3P] where P = (Fo^2 + 2Fc^2)/3
3584 reflections	(Δ/σ)max = 0.001
199 parameters	Δρmax = 0.37 e Å^−3
0 restraints	Δρmin = −0.19 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.13422 (6)	0.0558 (3)	0.23845 (8)	0.0219 (4)
C2	0.16556 (6)	−0.1087 (3)	0.22076 (8)	0.0227 (4)
C3	0.20772 (6)	−0.2482 (4)	0.26506 (9)	0.0247 (4)
H3A	0.1983	−0.4352	0.2683	0.030*
H3B	0.2379	−0.2445	0.2493	0.030*
C4	0.22005 (7)	−0.1257 (4)	0.32688 (9)	0.0269 (4)
H4A	0.2512	−0.1680	0.3545	0.032*
C4a	0.18963 (6)	0.0393 (4)	0.34516 (8)	0.0246 (4)
C5	0.20257 (7)	0.1559 (4)	0.40837 (9)	0.0327 (5)
H5A	0.1855	0.3283	0.4073	0.039*
H5B	0.2391	0.1873	0.4219	0.039*
C6	0.18702 (7)	−0.0257 (5)	0.45417 (9)	0.0374 (5)
H6A	0.2119	−0.1700	0.4652	0.045*
H6B	0.1885	0.0769	0.4916	0.045*
O7	0.12693 (6)	−0.3669 (3)	0.44837 (7)	0.0400 (4)
C7	0.13553 (7)	−0.1467 (4)	0.43262 (8)	0.0276 (4)
C8	0.09399 (6)	0.0128 (4)	0.38959 (8)	0.0230 (4)
H8A	0.0982	0.2048	0.3998	0.028*
C9a	0.13862 (6)	0.1112 (4)	0.30472 (8)	0.0217 (4)
H9	0.1338	0.3052	0.3090	0.026*
C9	0.09571 (6)	−0.0321 (4)	0.32386 (8)	0.0220 (4)
H9A	0.0634	0.0261	0.2966	0.026*
H9B	0.0989	−0.2240	0.3175	0.026*
C10	0.16304 (6)	−0.1652 (4)	0.15539 (9)	0.0243 (4)
O10	0.18388 (5)	−0.0343 (3)	0.12509 (7)	0.0341 (3)
O11	0.13893 (5)	−0.3903 (3)	0.13737 (6)	0.0292 (3)
C12	0.13454 (8)	−0.4625 (4)	0.07486 (9)	0.0331 (4)
H12A	0.1163	−0.6297	0.0658	0.050*
H12B	0.1680	−0.4827	0.0685	0.050*
H12C	0.1163	−0.3242	0.0479	0.050*
O13	0.07926 (5)	0.1123 (3)	0.13907 (6)	0.0288 (3)
C13	0.09221 (6)	0.1790 (4)	0.19162 (9)	0.0237 (4)
O14	0.06994 (5)	0.3708 (3)	0.21563 (6)	0.0294 (3)
C15	0.02879 (7)	0.5047 (4)	0.17351 (10)	0.0342 (5)
H15A	0.0151	0.6406	0.1953	0.051*
H15B	0.0025	0.3766	0.1557	0.051*
H15C	0.0409	0.5873	0.1412	0.051*
O16	0.04589 (5)	−0.0722 (3)	0.39226 (6)	0.0315 (3)
C17	0.03486 (8)	−0.0094 (5)	0.44818 (9)	0.0402 (5)
H17A	0.0013	−0.0736	0.4474	0.060*
H17B	0.0362	0.1824	0.4540	0.060*
H17C	0.0595	−0.0936	0.4817	0.060*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0220 (8)	0.0152 (8)	0.0297 (9)	−0.0028 (6)	0.0087 (7)	0.0002 (7)
C2	0.0231 (8)	0.0157 (8)	0.0308 (9)	−0.0043 (7)	0.0100 (7)	−0.0006 (7)
C3	0.0229 (8)	0.0186 (8)	0.0347 (10)	0.0018 (7)	0.0114 (7)	−0.0009 (8)
C4	0.0201 (8)	0.0263 (9)	0.0329 (10)	0.0012 (7)	0.0044 (7)	−0.0005 (8)
C4a	0.0197 (8)	0.0220 (9)	0.0308 (9)	−0.0034 (7)	0.0042 (7)	−0.0039 (7)
C5	0.0204 (8)	0.0376 (11)	0.0367 (11)	−0.0002 (8)	0.0014 (8)	−0.0144 (9)
C6	0.0277 (10)	0.0518 (14)	0.0282 (10)	0.0071 (9)	−0.0006 (8)	−0.0074 (10)
O7	0.0576 (10)	0.0290 (8)	0.0345 (8)	0.0094 (7)	0.0143 (7)	0.0038 (6)
C7	0.0337 (10)	0.0274 (10)	0.0217 (9)	0.0066 (8)	0.0075 (7)	−0.0048 (7)
C8	0.0208 (8)	0.0216 (9)	0.0265 (9)	−0.0007 (7)	0.0058 (7)	−0.0037 (7)
C9a	0.0201 (8)	0.0152 (8)	0.0300 (9)	0.0017 (6)	0.0068 (7)	−0.0023 (7)
C9	0.0203 (8)	0.0214 (9)	0.0239 (8)	−0.0016 (7)	0.0051 (7)	−0.0012 (7)
C10	0.0239 (8)	0.0176 (8)	0.0331 (10)	0.0005 (7)	0.0106 (7)	−0.0005 (7)
O10	0.0361 (7)	0.0318 (8)	0.0394 (8)	−0.0100 (6)	0.0188 (6)	0.0000 (6)
O11	0.0420 (8)	0.0204 (7)	0.0282 (7)	−0.0082 (6)	0.0145 (6)	−0.0037 (5)
C12	0.0470 (12)	0.0273 (10)	0.0257 (9)	−0.0047 (9)	0.0108 (8)	−0.0018 (8)
O13	0.0279 (6)	0.0263 (7)	0.0306 (7)	−0.0028 (6)	0.0046 (5)	−0.0004 (6)
C13	0.0219 (8)	0.0190 (9)	0.0315 (9)	−0.0024 (7)	0.0094 (7)	0.0027 (7)
O14	0.0293 (7)	0.0266 (7)	0.0323 (7)	0.0094 (6)	0.0080 (5)	0.0037 (6)
C15	0.0294 (9)	0.0324 (11)	0.0399 (11)	0.0089 (8)	0.0077 (8)	0.0083 (9)
O16	0.0253 (6)	0.0459 (9)	0.0250 (7)	−0.0082 (6)	0.0098 (5)	−0.0067 (6)
C17	0.0311 (10)	0.0643 (16)	0.0278 (10)	−0.0006 (10)	0.0122 (8)	−0.0070 (10)

Geometric parameters (Å, º)

C1—C2	1.338 (2)	C8—H8A	1.000
C1—C13	1.494 (3)	C9a—C9	1.548 (2)
C1—C9a	1.510 (2)	C9a—H9	1.000
C2—C10	1.501 (3)	C9—H9A	0.990
C2—C3	1.504 (3)	C9—H9B	0.990
C3—C4	1.495 (3)	C10—O10	1.207 (2)
C3—H3A	0.990	C10—O11	1.331 (2)
C3—H3B	0.990	O11—C12	1.445 (2)
C4—C4a	1.328 (3)	C12—H12A	0.980
C4—H4A	0.950	C12—H12B	0.980
C4a—C5	1.511 (3)	C12—H12C	0.980
C4a—C9a	1.515 (2)	O13—C13	1.205 (2)
C5—C6	1.535 (3)	C13—O14	1.342 (2)
C5—H5A	0.990	O14—C15	1.451 (2)
C5—H5B	0.990	C15—H15A	0.980
C6—C7	1.510 (3)	C15—H15B	0.980
C6—H6A	0.990	C15—H15C	0.980
C6—H6B	0.990	O16—C17	1.422 (2)
O7—C7	1.214 (3)	C17—H17A	0.980
C7—C8	1.532 (3)	C17—H17B	0.980
C8—O16	1.415 (2)	C17—H17C	0.980
C8—C9	1.528 (2)
C2—C1—C13	119.29 (17)	C1—C9a—C4a	112.51 (14)
C2—C1—C9a	121.86 (16)	C1—C9a—C9	109.12 (14)
C13—C1—C9a	118.80 (15)	C4a—C9a—C9	112.15 (15)
C1—C2—C10	123.51 (17)	C1—C9a—H9	108
C1—C2—C3	122.67 (17)	C4a—C9a—H9	108
C10—C2—C3	113.80 (15)	C9—C9a—H9	108
C4—C3—C2	112.56 (15)	C8—C9—C9a	115.40 (14)
C4—C3—H3A	109	C8—C9—H9A	108
C2—C3—H3A	109	C9a—C9—H9A	108
C4—C3—H3B	109	C8—C9—H9B	108
C2—C3—H3B	109	C9a—C9—H9B	108
H3A—C3—H3B	108	H9A—C9—H9B	108
C4a—C4—C3	123.34 (17)	O10—C10—O11	124.75 (18)
C4a—C4—H4A	118	O10—C10—C2	123.93 (17)
C3—C4—H4A	118	O11—C10—C2	111.05 (15)
C4—C4a—C5	122.24 (17)	C10—O11—C12	115.30 (15)
C4—C4a—C9a	121.77 (17)	O11—C12—H12A	110
C5—C4a—C9a	115.92 (15)	O11—C12—H12B	110
C4a—C5—C6	112.05 (17)	H12A—C12—H12B	110
C4a—C5—H5A	109	O11—C12—H12C	110
C6—C5—H5A	109	H12A—C12—H12C	110
C4a—C5—H5B	109	H12B—C12—H12C	110
C6—C5—H5B	109	O13—C13—O14	124.02 (17)
H5A—C5—H5B	108	O13—C13—C1	124.53 (17)
C7—C6—C5	115.50 (16)	O14—C13—C1	111.44 (16)
C7—C6—H6A	108	C13—O14—C15	115.68 (15)
C5—C6—H6A	108	O14—C15—H15A	110
C7—C6—H6B	108	O14—C15—H15B	110
C5—C6—H6B	108	H15A—C15—H15B	110
H6A—C6—H6B	108	O14—C15—H15C	110
O7—C7—C6	121.20 (19)	H15A—C15—H15C	110
O7—C7—C8	120.12 (18)	H15B—C15—H15C	110
C6—C7—C8	118.68 (18)	C8—O16—C17	113.25 (15)
O16—C8—C9	105.51 (13)	O16—C17—H17A	110
O16—C8—C7	111.62 (16)	O16—C17—H17B	110
C9—C8—C7	109.79 (14)	H17A—C17—H17B	110
O16—C8—H8A	110	O16—C17—H17C	110
C9—C8—H8A	110	H17A—C17—H17C	110
C7—C8—H8A	110	H17B—C17—H17C	110
C13—C1—C2—C10	4.0 (3)	C4—C4a—C9a—C1	−19.5 (3)
C9a—C1—C2—C10	−178.85 (15)	C5—C4a—C9a—C1	163.42 (16)
C13—C1—C2—C3	−177.85 (15)	C4—C4a—C9a—C9	104.0 (2)
C9a—C1—C2—C3	−0.7 (3)	C5—C4a—C9a—C9	−73.1 (2)
C1—C2—C3—C4	−17.1 (2)	O16—C8—C9—C9a	164.57 (15)
C10—C2—C3—C4	161.19 (15)	C7—C8—C9—C9a	−75.0 (2)
C2—C3—C4—C4a	16.6 (3)	C1—C9a—C9—C8	−177.97 (15)
C3—C4—C4a—C5	178.70 (18)	C4a—C9a—C9—C8	56.7 (2)
C3—C4—C4a—C9a	1.8 (3)	C1—C2—C10—O10	87.2 (2)
C4—C4a—C5—C6	−86.3 (2)	C3—C2—C10—O10	−91.1 (2)
C9a—C4a—C5—C6	90.8 (2)	C1—C2—C10—O11	−98.6 (2)
C4a—C5—C6—C7	−44.3 (2)	C3—C2—C10—O11	83.14 (18)
C5—C6—C7—O7	146.00 (19)	O10—C10—O11—C12	−5.8 (3)
C5—C6—C7—C8	−33.4 (3)	C2—C10—O11—C12	−179.95 (16)
O7—C7—C8—O16	23.7 (2)	C2—C1—C13—O13	11.8 (3)
C6—C7—C8—O16	−156.95 (16)	C9a—C1—C13—O13	−165.38 (17)
O7—C7—C8—C9	−93.0 (2)	C2—C1—C13—O14	−169.36 (15)
C6—C7—C8—C9	86.4 (2)	C9a—C1—C13—O14	13.4 (2)
C2—C1—C9a—C4a	18.9 (2)	O13—C13—O14—C15	−1.7 (3)
C13—C1—C9a—C4a	−163.99 (15)	C1—C13—O14—C15	179.47 (15)
C2—C1—C9a—C9	−106.25 (19)	C9—C8—O16—C17	−171.37 (17)
C13—C1—C9a—C9	70.87 (19)	C7—C8—O16—C17	69.4 (2)

(III) (3aS*,9R*,10aS*,10bR*)-9-methoxy-1,3a,4,6,7,8,9,10,10a,10b-decahydro-2-oxa- 3H-cyclohepta[e]inden-1,3,8-trione

Crystal data

C14H16O5	F(000) = 560
Mr = 264.27	Dx = 1.418 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 14.1076 (19) Å	Cell parameters from 5832 reflections
b = 11.3501 (15) Å	θ = 2.3–28.6°
c = 7.7762 (10) Å	µ = 0.11 mm^−1
β = 96.280 (2)°	T = 150 K
V = 1237.7 (3) Å^3	Block, colourless
Z = 4	0.42 × 0.40 × 0.31 mm

Data collection

Bruker SMART1000 CCD area-detector diffractometer	2437 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.033
Graphite monochromator	θmax = 28.6°, θmin = 2.3°
ω scans	h = −18→18
10858 measured reflections	k = −14→14
3047 independent reflections	l = −10→10

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.035	Hydrogen site location: geometrically placed, Me from delta-F
wR(F^2) = 0.100	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0563P)^2 + 0.2015P] where P = (Fo^2 + 2Fc^2)/3
2896 reflections	(Δ/σ)max = 0.001
173 parameters	Δρmax = 0.30 e Å^−3
0 restraints	Δρmin = −0.16 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.77569 (7)	0.23368 (8)	−0.02449 (12)	0.0432 (3)
C1	0.72962 (9)	0.29970 (10)	−0.12021 (14)	0.0275 (2)
O2	0.63996 (6)	0.26549 (7)	−0.19201 (11)	0.0327 (2)
C3A	0.66626 (8)	0.45603 (10)	−0.30640 (14)	0.0252 (2)
H3A	0.6851	0.4626	−0.4263	0.030*
O3	0.51962 (6)	0.34080 (9)	−0.36971 (13)	0.0414 (2)
C3	0.59817 (8)	0.35389 (10)	−0.29958 (15)	0.0284 (3)
C4	0.61806 (9)	0.57142 (10)	−0.25996 (15)	0.0316 (3)
H4A	0.6543	0.6393	−0.2989	0.038*
H4B	0.5526	0.5748	−0.3203	0.038*
C5A	0.68903 (8)	0.54864 (9)	0.04225 (14)	0.0235 (2)
C5	0.61415 (8)	0.57905 (10)	−0.06857 (16)	0.0289 (3)
H5	0.5575	0.6059	−0.0255	0.035*
C6	0.68550 (8)	0.55716 (11)	0.23423 (15)	0.0295 (3)
H6A	0.6959	0.4777	0.2855	0.035*
H6B	0.6210	0.5834	0.2562	0.035*
C7	0.76006 (9)	0.64285 (11)	0.32640 (15)	0.0304 (3)
H7A	0.7699	0.7105	0.2499	0.036*
H7B	0.7370	0.6734	0.4336	0.036*
O8	0.87525 (7)	0.53754 (9)	0.51270 (11)	0.0410 (2)
C8	0.85214 (8)	0.57778 (10)	0.36936 (14)	0.0272 (2)
C9	0.91203 (8)	0.55270 (10)	0.22123 (14)	0.0243 (2)
H9	0.9746	0.5191	0.2709	0.029*
C10b	0.75405 (7)	0.42122 (9)	−0.18265 (13)	0.0218 (2)
H10B	0.8099	0.4141	−0.2509	0.026*
C10	0.86242 (8)	0.46309 (9)	0.09406 (14)	0.0233 (2)
H10C	0.8376	0.3983	0.1617	0.028*
H10D	0.9109	0.4288	0.0258	0.028*
C10a	0.77980 (7)	0.51041 (9)	−0.03285 (13)	0.0202 (2)
H10A	0.8048	0.5823	−0.0872	0.024*
O11	0.92977 (6)	0.65651 (7)	0.12697 (10)	0.02546 (19)
C12	0.98894 (8)	0.73858 (11)	0.22894 (15)	0.0289 (3)
H12A	0.9524	0.7746	0.3154	0.043*
H12B	1.0105	0.8001	0.1538	0.043*
H12C	1.0444	0.6973	0.2874	0.043*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0579 (6)	0.0245 (4)	0.0426 (5)	−0.0030 (4)	−0.0142 (5)	0.0061 (4)
C1	0.0338 (6)	0.0243 (5)	0.0240 (5)	−0.0022 (4)	0.0012 (4)	−0.0015 (4)
O2	0.0340 (5)	0.0278 (4)	0.0360 (5)	−0.0084 (3)	0.0021 (4)	0.0012 (3)
C3A	0.0275 (5)	0.0285 (6)	0.0190 (5)	−0.0037 (4)	−0.0004 (4)	0.0015 (4)
O3	0.0274 (5)	0.0442 (5)	0.0509 (6)	−0.0045 (4)	−0.0039 (4)	−0.0094 (4)
C3	0.0278 (6)	0.0304 (6)	0.0271 (6)	−0.0021 (4)	0.0033 (4)	−0.0051 (4)
C4	0.0350 (6)	0.0272 (6)	0.0299 (6)	0.0023 (5)	−0.0092 (5)	0.0039 (5)
C5A	0.0248 (5)	0.0218 (5)	0.0239 (5)	0.0013 (4)	0.0035 (4)	−0.0010 (4)
C5	0.0258 (5)	0.0264 (6)	0.0337 (6)	0.0050 (4)	0.0006 (5)	−0.0018 (5)
C6	0.0264 (5)	0.0376 (7)	0.0255 (5)	0.0009 (5)	0.0075 (4)	−0.0021 (5)
C7	0.0356 (6)	0.0323 (6)	0.0240 (5)	0.0014 (5)	0.0063 (5)	−0.0060 (4)
O8	0.0438 (5)	0.0540 (6)	0.0234 (4)	−0.0127 (4)	−0.0042 (4)	0.0112 (4)
C8	0.0330 (6)	0.0259 (5)	0.0216 (5)	−0.0080 (4)	−0.0015 (4)	0.0002 (4)
C9	0.0250 (5)	0.0231 (5)	0.0237 (5)	0.0007 (4)	−0.0028 (4)	0.0023 (4)
C10b	0.0236 (5)	0.0228 (5)	0.0191 (5)	−0.0011 (4)	0.0027 (4)	0.0005 (4)
C10	0.0230 (5)	0.0216 (5)	0.0247 (5)	0.0029 (4)	−0.0009 (4)	−0.0005 (4)
C10a	0.0215 (5)	0.0195 (5)	0.0192 (5)	0.0001 (4)	0.0009 (4)	0.0010 (4)
O11	0.0286 (4)	0.0260 (4)	0.0211 (4)	−0.0056 (3)	−0.0006 (3)	0.0003 (3)
C12	0.0296 (6)	0.0283 (6)	0.0279 (6)	−0.0060 (4)	−0.0004 (5)	−0.0038 (4)

Geometric parameters (Å, º)

O1—C1	1.1967 (14)	C7—C8	1.4998 (17)
C1—O2	1.3813 (14)	C7—H7A	0.990
C1—C10b	1.5144 (15)	C7—H7B	0.990
O2—C3	1.3950 (15)	O8—C8	1.2156 (14)
C3A—C3	1.5102 (16)	C8—C9	1.5280 (16)
C3A—C10b	1.5348 (15)	C9—O11	1.4242 (13)
C3A—C4	1.5368 (17)	C9—C10	1.5332 (15)
C3A—H3A	1.000	C9—H9	1.000
O3—C3	1.1896 (14)	C10b—C10a	1.5561 (14)
C4—C5	1.4979 (17)	C10b—H10B	1.000
C4—H4A	0.990	C10—C10a	1.5392 (14)
C4—H4B	0.990	C10—H10C	0.990
C5A—C5	1.3336 (16)	C10—H10D	0.990
C5A—C6	1.5023 (16)	C10a—H10A	1.000
C5A—C10a	1.5273 (14)	O11—C12	1.4311 (13)
C5—H5	0.950	C12—H12A	0.980
C6—C7	1.5495 (17)	C12—H12B	0.980
C6—H6A	0.990	C12—H12C	0.980
C6—H6B	0.990
O1—C1—O2	119.10 (11)	H7A—C7—H7B	108
O1—C1—C10b	129.99 (11)	O8—C8—C7	121.88 (11)
O2—C1—C10b	110.91 (9)	O8—C8—C9	120.42 (11)
C1—O2—C3	110.40 (9)	C7—C8—C9	117.43 (9)
C3—C3A—C10b	104.66 (9)	O11—C9—C8	112.13 (9)
C3—C3A—C4	110.27 (10)	O11—C9—C10	108.09 (8)
C10b—C3A—C4	114.81 (9)	C8—C9—C10	111.03 (9)
C3—C3A—H3A	109	O11—C9—H9	109
C10b—C3A—H3A	109	C8—C9—H9	109
C4—C3A—H3A	109	C10—C9—H9	109
O3—C3—O2	119.77 (11)	C1—C10b—C3A	103.84 (9)
O3—C3—C3A	130.09 (12)	C1—C10b—C10a	113.28 (8)
O2—C3—C3A	110.15 (9)	C3A—C10b—C10a	114.09 (9)
C5—C4—C3A	110.37 (9)	C1—C10b—H10B	109
C5—C4—H4A	110	C3A—C10b—H10B	109
C3A—C4—H4A	110	C10a—C10b—H10B	109
C5—C4—H4B	110	C9—C10—C10a	116.25 (9)
C3A—C4—H4B	110	C9—C10—H10C	108
H4A—C4—H4B	108	C10a—C10—H10C	108
C5—C5A—C6	121.03 (10)	C9—C10—H10D	108
C5—C5A—C10a	117.67 (10)	C10a—C10—H10D	108
C6—C5A—C10a	121.24 (9)	H10C—C10—H10D	107
C5A—C5—C4	120.96 (11)	C5A—C10a—C10	117.50 (9)
C5A—C5—H5	120	C5A—C10a—C10b	109.52 (8)
C4—C5—H5	120	C10—C10a—C10b	110.57 (8)
C5A—C6—C7	113.92 (10)	C5A—C10a—H10A	106
C5A—C6—H6A	109	C10—C10a—H10A	106
C7—C6—H6A	109	C10b—C10a—H10A	106
C5A—C6—H6B	109	C9—O11—C12	112.21 (8)
C7—C6—H6B	109	O11—C12—H12A	110
H6A—C6—H6B	108	O11—C12—H12B	110
C8—C7—C6	108.76 (10)	H12A—C12—H12B	110
C8—C7—H7A	110	O11—C12—H12C	110
C6—C7—H7A	110	H12A—C12—H12C	110
C8—C7—H7B	110	H12B—C12—H12C	110
C6—C7—H7B	110
O1—C1—O2—C3	−179.81 (11)	O1—C1—C10b—C3A	178.24 (13)
C10b—C1—O2—C3	−0.61 (13)	O2—C1—C10b—C3A	−0.86 (12)
C1—O2—C3—O3	−178.30 (11)	O1—C1—C10b—C10a	−57.46 (16)
C1—O2—C3—C3A	1.88 (13)	O2—C1—C10b—C10a	123.45 (10)
C10b—C3A—C3—O3	177.88 (12)	C3—C3A—C10b—C1	1.84 (11)
C4—C3A—C3—O3	53.89 (16)	C4—C3A—C10b—C1	122.87 (10)
C10b—C3A—C3—O2	−2.33 (12)	C3—C3A—C10b—C10a	−121.94 (10)
C4—C3A—C3—O2	−126.31 (10)	C4—C3A—C10b—C10a	−0.90 (13)
C3—C3A—C4—C5	76.60 (12)	O11—C9—C10—C10a	−45.97 (12)
C10b—C3A—C4—C5	−41.30 (13)	C8—C9—C10—C10a	77.39 (12)
C6—C5A—C5—C4	179.50 (11)	C5—C5A—C10a—C10	−173.76 (10)
C10a—C5A—C5—C4	2.29 (16)	C6—C5A—C10a—C10	9.04 (14)
C3A—C4—C5—C5A	43.06 (15)	C5—C5A—C10a—C10b	−46.54 (13)
C5—C5A—C6—C7	−118.78 (12)	C6—C5A—C10a—C10b	136.25 (10)
C10a—C5A—C6—C7	58.34 (14)	C9—C10—C10a—C5A	−68.11 (12)
C5A—C6—C7—C8	−85.84 (12)	C9—C10—C10a—C10b	165.18 (9)
C6—C7—C8—O8	−98.50 (13)	C1—C10b—C10a—C5A	−74.89 (11)
C6—C7—C8—C9	75.50 (12)	C3A—C10b—C10a—C5A	43.64 (12)
O8—C8—C9—O11	−133.25 (11)	C1—C10b—C10a—C10	56.13 (11)
C7—C8—C9—O11	52.65 (13)	C3A—C10b—C10a—C10	174.66 (9)
O8—C8—C9—C10	105.73 (12)	C8—C9—O11—C12	66.33 (11)
C7—C8—C9—C10	−68.37 (12)	C10—C9—O11—C12	−170.97 (9)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6B···O3^i	0.99	2.42	3.3900 (16)	168

Symmetry code: (i) −x+1, −y+1, −z.

(IV) (1S*,2R*,9S*,10aR*)-9-methoxy-8-oxo-1,2,3,5,6,7,8,9,10,10a-decahydro- benzocyclooctene-1,2-dicarboxylic acid

Crystal data

C15H20O6	Dx = 1.421 Mg m^−3
Mr = 296.31	Synchrotron radiation, λ = 0.6892 Å
Orthorhombic, Pbca	Cell parameters from 5549 reflections
a = 14.676 (2) Å	θ = 3.2–29.1°
b = 9.967 (2) Å	µ = 0.11 mm^−1
c = 18.937 (3) Å	T = 150 K
V = 2770.0 (8) Å^3	Tablet, colourless
Z = 8	0.06 × 0.05 × 0.01 mm
F(000) = 1264

Data collection

Bruker SMART CCD area-detector on SRS Station 9.8 diffractometer	1769 reflections with I > 2σ(I)
Radiation source: synchrotron storage ring	Rint = 0.136
Germanium monochromator	θmax = 26.0°, θmin = 2.6°
0.15 degree ω scans	h = −20→17
18905 measured reflections	k = −14→12
2715 independent reflections	l = −25→24

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.084	H-atom parameters constrained
wR(F^2) = 0.231	w = 1/[σ^2(Fo^2) + (0.123P)^2 + 1.776P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max = 0.001
2715 reflections	Δρmax = 0.53 e Å^−3
192 parameters	Δρmin = −0.29 e Å^−3
0 restraints

Special details

Experimental. The Daresbury Laboratory SRS was the X-ray source.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.0734 (2)	0.8207 (3)	0.69360 (17)	0.0230 (8)
H1	0.0091	0.8484	0.7030	0.028*
C2	0.1182 (2)	0.9317 (4)	0.65095 (18)	0.0264 (8)
H2	0.1138	1.0150	0.6802	0.032*
C3	0.2209 (2)	0.9072 (4)	0.6379 (2)	0.0319 (9)
H3A	0.2286	0.8571	0.5931	0.038*
H3B	0.2521	0.9947	0.6326	0.038*
C4	0.2649 (3)	0.8303 (4)	0.6964 (2)	0.0347 (10)
H4	0.3283	0.8130	0.6917	0.042*
C4a	0.2247 (2)	0.7834 (4)	0.75456 (19)	0.0291 (9)
C5	0.2813 (3)	0.7076 (4)	0.8080 (2)	0.0355 (10)
H5A	0.3404	0.6851	0.7858	0.043*
H5B	0.2499	0.6220	0.8185	0.043*
C6	0.3006 (3)	0.7775 (5)	0.8774 (2)	0.0353 (10)
H6A	0.3115	0.8737	0.8675	0.042*
H6B	0.3577	0.7402	0.8971	0.042*
C7	0.2260 (3)	0.7670 (5)	0.9343 (2)	0.0346 (10)
H7A	0.2080	0.6718	0.9396	0.042*
H7B	0.2512	0.7976	0.9800	0.042*
C8	0.1430 (3)	0.8488 (4)	0.91697 (17)	0.0269 (8)
O8	0.1430 (2)	0.9700 (3)	0.92010 (13)	0.0369 (7)
C9	0.0597 (2)	0.7717 (4)	0.89150 (18)	0.0275 (8)
H9	0.0472	0.6969	0.9254	0.033*
O9	−0.01852 (17)	0.8565 (3)	0.88839 (13)	0.0312 (7)
C9M	−0.0651 (3)	0.8631 (4)	0.95555 (19)	0.0344 (9)
H9M1	−0.1181	0.9224	0.9515	0.052*
H9M2	−0.0235	0.8982	0.9915	0.052*
H9M3	−0.0854	0.7730	0.9692	0.052*
C10	0.0754 (3)	0.7122 (4)	0.81838 (18)	0.0271 (8)
H10A	0.0159	0.6851	0.7983	0.033*
H10B	0.1131	0.6303	0.8232	0.033*
C10a	0.1227 (2)	0.8084 (4)	0.76623 (17)	0.0232 (8)
H10C	0.1184	0.8994	0.7883	0.028*
C11	0.0704 (2)	0.6916 (4)	0.65070 (18)	0.0254 (8)
O11	0.0998 (2)	0.6811 (3)	0.59198 (14)	0.0397 (7)
O12	0.0266 (2)	0.5920 (3)	0.68351 (15)	0.0431 (8)
H12	0.0220	0.5261	0.6561	0.065*
C21	0.0674 (3)	0.9599 (4)	0.58358 (18)	0.0278 (8)
O21	−0.01638 (18)	0.9402 (3)	0.58095 (14)	0.0363 (7)
O22	0.11397 (19)	1.0089 (3)	0.53182 (13)	0.0376 (7)
H22	0.0791	1.0245	0.4976	0.056*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0146 (16)	0.032 (2)	0.0221 (17)	0.0015 (15)	−0.0015 (13)	−0.0038 (14)
C2	0.0232 (19)	0.035 (2)	0.0212 (17)	0.0019 (16)	−0.0003 (14)	−0.0035 (14)
C3	0.0206 (19)	0.049 (3)	0.0264 (19)	−0.0043 (17)	−0.0004 (15)	0.0040 (17)
C4	0.0162 (18)	0.055 (3)	0.033 (2)	−0.0004 (18)	0.0018 (15)	0.0031 (18)
C4a	0.0206 (18)	0.039 (2)	0.0281 (19)	−0.0002 (16)	−0.0008 (15)	−0.0003 (16)
C5	0.0169 (18)	0.052 (3)	0.038 (2)	0.0092 (18)	0.0011 (16)	0.0073 (18)
C6	0.023 (2)	0.051 (3)	0.032 (2)	0.0015 (18)	−0.0072 (16)	0.0084 (18)
C7	0.031 (2)	0.049 (2)	0.0237 (18)	−0.0066 (19)	−0.0055 (16)	0.0107 (17)
C8	0.031 (2)	0.036 (2)	0.0131 (16)	−0.0027 (16)	0.0043 (14)	−0.0032 (14)
O8	0.0394 (17)	0.0408 (19)	0.0304 (14)	−0.0066 (13)	0.0042 (12)	−0.0054 (12)
C9	0.0218 (18)	0.036 (2)	0.0250 (18)	0.0003 (16)	0.0047 (14)	0.0027 (15)
O9	0.0253 (14)	0.0441 (16)	0.0240 (13)	0.0061 (12)	0.0036 (10)	0.0047 (11)
C9M	0.028 (2)	0.048 (2)	0.0271 (19)	0.0000 (19)	0.0097 (16)	0.0030 (17)
C10	0.0247 (18)	0.033 (2)	0.0233 (17)	−0.0033 (16)	0.0012 (14)	−0.0007 (14)
C10a	0.0202 (17)	0.0314 (19)	0.0180 (16)	−0.0036 (15)	−0.0021 (13)	−0.0028 (13)
C11	0.0184 (17)	0.035 (2)	0.0230 (18)	0.0000 (16)	−0.0054 (14)	−0.0040 (15)
O11	0.0438 (17)	0.0438 (17)	0.0314 (15)	−0.0048 (14)	0.0123 (13)	−0.0094 (12)
O12	0.056 (2)	0.0425 (18)	0.0309 (15)	−0.0190 (15)	0.0089 (14)	−0.0112 (12)
C21	0.026 (2)	0.033 (2)	0.0249 (18)	0.0011 (16)	0.0018 (15)	−0.0047 (15)
O21	0.0254 (15)	0.0487 (18)	0.0348 (15)	0.0000 (12)	−0.0026 (11)	0.0043 (12)
O22	0.0335 (15)	0.0551 (18)	0.0243 (13)	0.0004 (14)	−0.0010 (11)	0.0096 (13)

Geometric parameters (Å, º)

C1—C2	1.520 (5)	C7—H7A	0.990
C1—C11	1.522 (5)	C7—H7B	0.990
C1—C10a	1.559 (4)	C8—O8	1.210 (5)
C1—H1	1.000	C8—C9	1.523 (5)
C2—C21	1.504 (5)	C9—O9	1.427 (4)
C2—C3	1.547 (5)	C9—C10	1.524 (5)
C2—H2	1.000	C9—H9	1.000
C3—C4	1.494 (5)	O9—C9M	1.445 (4)
C3—H3A	0.990	C9M—H9M1	0.980
C3—H3B	0.990	C9M—H9M2	0.980
C4—C4a	1.335 (5)	C9M—H9M3	0.980
C4—H4	0.950	C10—C10a	1.541 (5)
C4a—C5	1.512 (5)	C10—H10A	0.990
C4a—C10a	1.533 (5)	C10—H10B	0.990
C5—C6	1.513 (6)	C10a—H10C	1.000
C5—H5A	0.990	C11—O11	1.197 (4)
C5—H5B	0.990	C11—O12	1.336 (5)
C6—C7	1.540 (6)	O12—H12	0.840
C6—H6A	0.990	C21—O21	1.247 (5)
C6—H6B	0.990	C21—O22	1.291 (4)
C7—C8	1.502 (6)	O22—H22	0.840
C2—C1—C11	110.2 (3)	C8—C7—H7B	109
C2—C1—C10a	109.0 (3)	C6—C7—H7B	109
C11—C1—C10a	114.7 (3)	H7A—C7—H7B	108
C2—C1—H1	108	O8—C8—C7	122.1 (4)
C11—C1—H1	108	O8—C8—C9	121.3 (4)
C10a—C1—H1	108	C7—C8—C9	116.5 (3)
C21—C2—C1	111.9 (3)	O9—C9—C8	111.1 (3)
C21—C2—C3	112.1 (3)	O9—C9—C10	108.4 (3)
C1—C2—C3	113.0 (3)	C8—C9—C10	111.2 (3)
C21—C2—H2	106	O9—C9—H9	109
C1—C2—H2	106	C8—C9—H9	109
C3—C2—H2	106	C10—C9—H9	109
C4—C3—C2	112.6 (3)	C9—O9—C9M	111.8 (3)
C4—C3—H3A	109	O9—C9M—H9M1	110
C2—C3—H3A	109	O9—C9M—H9M2	110
C4—C3—H3B	109	H9M1—C9M—H9M2	110
C2—C3—H3B	109	O9—C9M—H9M3	110
H3A—C3—H3B	108	H9M1—C9M—H9M3	110
C4a—C4—C3	126.9 (3)	H9M2—C9M—H9M3	110
C4a—C4—H4	117	C9—C10—C10a	114.1 (3)
C3—C4—H4	117	C9—C10—H10A	109
C4—C4a—C5	119.0 (3)	C10a—C10—H10A	109
C4—C4a—C10a	119.6 (3)	C9—C10—H10B	109
C5—C4a—C10a	121.4 (3)	C10a—C10—H10B	109
C4a—C5—C6	117.0 (4)	H10A—C10—H10B	108
C4a—C5—H5A	108	C4a—C10a—C10	115.5 (3)
C6—C5—H5A	108	C4a—C10a—C1	109.8 (3)
C4a—C5—H5B	108	C10—C10a—C1	113.9 (3)
C6—C5—H5B	108	C4a—C10a—H10C	106
H5A—C5—H5B	107	C10—C10a—H10C	106
C5—C6—C7	116.3 (3)	C1—C10a—H10C	106
C5—C6—H6A	108	O11—C11—O12	122.7 (3)
C7—C6—H6A	108	O11—C11—C1	124.0 (3)
C5—C6—H6B	108	O12—C11—C1	113.2 (3)
C7—C6—H6B	108	C11—O12—H12	110
H6A—C6—H6B	107	O21—C21—O22	123.5 (3)
C8—C7—C6	112.8 (3)	O21—C21—C2	119.6 (3)
C8—C7—H7A	109	O22—C21—C2	116.9 (3)
C6—C7—H7A	109	C21—O22—H22	110
C11—C1—C2—C21	59.8 (4)	O9—C9—C10—C10a	79.2 (4)
C10a—C1—C2—C21	−173.5 (3)	C8—C9—C10—C10a	−43.2 (4)
C11—C1—C2—C3	−67.9 (4)	C4—C4a—C10a—C10	159.2 (4)
C10a—C1—C2—C3	58.8 (4)	C5—C4a—C10a—C10	−21.5 (5)
C21—C2—C3—C4	−158.2 (3)	C4—C4a—C10a—C1	28.7 (5)
C1—C2—C3—C4	−30.7 (5)	C5—C4a—C10a—C1	−152.0 (3)
C2—C3—C4—C4a	0.7 (6)	C9—C10—C10a—C4a	101.7 (4)
C3—C4—C4a—C5	−179.9 (4)	C9—C10—C10a—C1	−129.9 (3)
C3—C4—C4a—C10a	−0.5 (6)	C2—C1—C10a—C4a	−56.6 (4)
C4—C4a—C5—C6	108.8 (4)	C11—C1—C10a—C4a	67.5 (4)
C10a—C4a—C5—C6	−70.5 (5)	C2—C1—C10a—C10	172.2 (3)
C4a—C5—C6—C7	83.6 (5)	C11—C1—C10a—C10	−63.8 (4)
C5—C6—C7—C8	−71.5 (5)	C2—C1—C11—O11	0.3 (5)
C6—C7—C8—O8	−72.2 (5)	C10a—C1—C11—O11	−123.1 (4)
C6—C7—C8—C9	104.8 (4)	C2—C1—C11—O12	−176.0 (3)
O8—C8—C9—O9	−12.9 (4)	C10a—C1—C11—O12	60.6 (4)
C7—C8—C9—O9	170.1 (3)	C1—C2—C21—O21	29.3 (5)
O8—C8—C9—C10	107.9 (4)	C3—C2—C21—O21	157.5 (3)
C7—C8—C9—C10	−69.1 (4)	C1—C2—C21—O22	−153.3 (3)
C8—C9—O9—C9M	−86.3 (3)	C3—C2—C21—O22	−25.2 (5)
C10—C9—O9—C9M	151.2 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O12—H12···O9^i	0.84	1.89	2.716 (4)	168
O22—H22···O21^ii	0.84	1.78	2.621 (4)	174

Symmetry codes: (i) −x, y−1/2, −z+3/2; (ii) −x, −y+2, −z+1.