Two isomeric butadiene–N-(acetoxy­phenyl)maleimide Diels–Alder adducts: supramolecular structure directed by C—H...X (X = O and π) hydrogen bonds and perpendicular dipole carbonyl–carbonyl inter­actions

The mol­ecular and supramolecular structures of 2-(1,3-dioxo-2,3,3a,4,7,7a-hexa­hydro-1H-isoindol-2-yl)phenyl acetate, C₁₆-H₁₅NO₄, (I), and its para isomer, 4-(1,3-dioxo-2,3,3a,4,7,7a-hexa­hydro-1H-isoindol-2-yl)phenyl acetate, (II), are reported. The torsion angle between the succinimide and benzene rings depends on the position of the acet­oxy substitution [89.7 (1) and 61.9 (1)° for (I) and (II), respectively]. The twist of the acet­oxy group relative to the mean plane of the benzene ring is almost independent of the acet­oxy position [66.0 (1) and 70.0 (1)°]. Packing inter­actions for both compounds include soft C—H...X (X = O and Ph) inter­actions, forming chains of centrosymmetric dimers and inter­linked chains for (I) and (II), respectively. In addition, three perpendicular dipole C=O...C=O inter­actions contribute to the supramolecular structure of (II).

S1. Comment

Substituted N-aryl maleimides have been used to control the stereochemistry of Diels–Alder cycloadditions (Kitagawa et al., 1998). On the grounds of [Depending on?] the appropriate selection of the o-substituent, the N—Ar torsion angle and the barrier to rotation is increased in comparison to the unsubstituted N—Ar maleimides (Curran et al., 1994). More recently, molecular induced recognition between the diene and maleimide have been used to control the stereochemistry of cycloaddition reactions (Bennes et al., 2001). However, the X-ray structures of only five Diels–Alder adducts derived from butadiene and substituted N—Ar maleimides have been reported, in contrast to almost forty N—Ar unsubstituted adducts (Cambridge Structural Database, Version of May 2005; Allen, 2002). Previously, the molecular and supramolecular structures of two Diels–Alder adducts between ortho- and para-N-acetoxyphenylmaleimides and furan, were reported (Trujillo-Ferrara et al., 2004). The molecular and supramolecular structures of the Diels–Alder adducts 2-(1,3-dioxo-2,3,3a,4,7,7a-hexahydro-1H-isoindol-2-yl)phenyl acetate, (I), and its para-isomer (II), are analyzed here. Compounds (I) and (II) crystallize in the monoclinic space groups P2₁/n and P2₁/c, respectively. Their molecular structures are shown in Figs. 1 and 2, and selected bond lengths and angles are listed in Tables 1 and 3, respectively. In both compounds, the succinimide group (C1/O1/N2/C3/O3/C3A/C7A) has a mean deviation from the plane of 0.002 Å in both compounds, and the cyclohexene ring exhibits a boat-like conformation. The phenyl ring is twisted relative to the succinimide ring by 89.7 (1)° in (I), the ortho-isomer, and by 61.9 (1)° in (II), the para-isomer. These results are in agreement with the expected values for the necessary twist to relieve unfavorable steric interactions between the o-acetoxy group, on the C₆H₄ ring, and the succinimide carbonyl groups. The twist exhibited by (I) is equivalent to the value found in other ortho ^tBu (Curran et al., 1994) or F-substituted Diels–Alder adducts (Li et al., 2005), but in this last compound and in (I), the ortho substituent points to the folded face of the cyclohexene ring. The acetoxy group is twisted by 66.0 (1) and 70.0 (1)° from the mean plane of the C₆H₄ ring in (I) and (II), respectively. These values contrast with the broad range found for Diels–Alder adducts derived from o- and p-N-acetoxyphenyl maleimides and furan (Trujillo-Ferrara et al., 2004).

The supramolecular structure of both compounds is determined by soft C—H···X (X = O and π) interactions (Steiner, 2002; Umezawa et al., 1998) and by carbonyl–carbonyl interactions, in the case of (II). The hydrogen-bonding geometry (and all symmetry codes) is listed in Tables 2 and 4 for (I) and (II), respectively. In (I), a centrosymmetric ring motif having graph set R₂²(18) (Bernstein et al., 1995) is formed by C16—H16A···O3ⁱ interactions, involving a CH₃ hydrogen donor and a succinimide carbonyl group as the acceptor. Although weak, the geometry of this Csp³—H···O interaction (Table 2) falls within the accepted ranges (Steiner & Desiraju, 1998). These dimers are interlinked by C12—H12···O15ⁱⁱ interactions between an aromatic H atom and the acetoxycarbonyl group (Table 2). Thus, chains of rings developing along the [3 9 13] direction, are formed (Fig. 3). In (II), antiparallel chains having graph-set notation C(6) are formed by C13—H13···O3ⁱⁱⁱ interactions, and these develop along the b axis (Table 4). The chains are interlinked by C7A—H7A···Cg3^iv interactions between an axial H atom at the ring fusion and the C₆H₄ ring of a neighboring molecule (Table 4, where Cg3 is the centroid of the C8—C13 ring) along the [504] direction (Fig. 4). Besides C—H···X (X = O and π) hydrogen bonding, two carbonyl–carbonyl interactions contribute to the overall molecular architecture. Both imide carbonyl groups, C1═O1 and C3═O3, are simultaneously involved in perpendicular dipole interactions with the acetoxy carbonyl group C15═O15 [O15···C3 = 3.152 (2) Å and C15═O5···C3^v = 139.3 (2)°; O15···C1 = 3.314 (2) Å and C15═ O15···C1^v = 155.2 (2)°; symmetry code: (v) x, −y + 3/2, z + 1/2 (please check; codes iv and v are the same)]. The O atom of the acetoxy carbonyl group C15═O15 donates electronic density to the C atoms of both imide carbonyl groups C1═O1 and C3═O3. The donor–aceptor roles of the C1=O1 and C15=O15 carbonyl groups are exchanged in the third carbonyl interaction C1═O1···C15^vi [O1···C15 = 3.160 (2) Å and C1═O1···C15^vi = 152.1 (2)°; symmetry code: (vi) x, −y + 5/2, + z − 1/2]. Consequently, four-membered infinite antiparallel chains of rings zigzaging along the [010] direction are formed (Fig. 4). It is worthy of mention that the C···O distances fall below the cut-off at 3.6 Å and the C═O···C angles are in agreement with the average value of 159.7 (7)° characteristic of this dipole–dipole interaction (Allen et al., 1998). Theoretical calculations have shown that this motif is frequently found in structures containing weak hydrogen-bonding donors and its strength is comparable to a C—H···O hydrogen bond (Allen et al., 1998).

A brief comparison with the analogous Diels–Alder adducts from furan (Trujillo-Ferrara et al., 2004), shows that the carbonyl group from the acetoxycarbonyl group, at least one carbonyl group from the succinimide ring and the C₆H₄ ring are always engaged as acceptors in hydrogen bonding, whereas the OCH₃, Csp³H (axial) and Csp²H (aryl) H atoms always participate as hydrogen-bonding donors. However, instead of the tetrameric aggregates present in the supramolecular structure of furan-derivatives, butadiene derivatives (I) and (II) arrange in chains.

S2. Experimental

Diels–Alder adducts (I) and (II) were obtained by the reaction between 1H-pyrrole-1-(2'-acetoxyphenyl)-2,5-dione or 1H-pyrrole-1-(4'-acetoxyphenyl)-2,5-dione (0.25 g, 1.8 mmol) and sulfolene (0.52 g, 2.2 mmol) dissolved in xylene (1.5 ml) in a sealed ampoule at 413 K for 10 h. The products crystallized as white solids in 82 and 85% yield, respectively. In both cases, crystals suitable for X-ray analysis were obtained from chloroform solutions by slow hexane diffusion. For (I) (m.p. 706–709 K) IR (KBr) ν cm⁻¹: 1770, 1704 (C═O), 1596 (C═C), 1366 (OAc), 1344, 1318(C—N); ¹H NMR (p.p.m.): δ 7.43 (td, 1H, H_p), 7.32 and 7.29 (m, 1H each, H_m), 7.26 (m, 1H, H_o), 6.00 (t, 2H, H5,6), 3.26 (dd, 2H, H3a,7a), 2.71 and 2.73 (ddd, 4H, H4,7), 2.19 (s, 3H, Me); ¹³C NMR (p.p.m.): δ 178.2 (C1,3), 167.6 (COO), 145.8 and 129.1 (C_o), 129.7 (C_i), 128.6 (C_p), 127.5 (C5,6), 126.0 and 123.6 (C_m), 39.2 (C3a,7a), 23.3 (C4,7), 20.8 (Me); MS m/z (%) 285 (6) (M⁺), 243 (100), 181 (1), 110 (95), 80 (34). For (II) (m.p. 688–691 K) IR (KBr) ν cm⁻¹: 1752, 1716 (C═O), 1598 (C═ C), 1344 (OAc), 1344 (C—N); ¹H NMR (p.p.m.): δ 7.29 (d, 2H, H_o), 7.26 (d, 2H, H_m), 5.95 (t, 2H, H5,6), 3.20 (dt, 2H, H3a,7a), 2.67 and 2.28 (m, 4H, H4,7), 2.27 (s, 3H, CH₃); ¹³C NMR (p.p.m.): δ 179.1 (C1,3), 169.0 (COO), 150.2 (C_p), 129.5 (C_i), 127.8 (C_o), 127.4 (C5,6), 122.2 (C_m), 39.2 (C3a,7a), 23.7 (C4,7), 21.1 (Me); MS m/z (%) 285 (6) (M⁺), 243 (100), 189 (4), 135 (15), 110 (3), 80 (46).

S3. Refinement

All H atoms were refined as riding on their parent atoms, with C—H distances in the range 0.93–0.98 Å, and with U_iso(H) value of 1.5U_eq(C) for methyl H atoms and 1.2U_eq(C) for other H atoms. The centroid of a set of atoms was calculated using the program Mercury (Bruno et al., 2002).

Computing details

For both compounds, data collection: CAD-4 EXPRESS (Enraf–Nonius, 1995); cell refinement: CAD-4 EXPRESS; data reduction: JANA98 (Vaclav, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: WinGX (Farrugia, 1999); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The molecular structure of the title ortho-Diels–Alder adduct (I), with displacement ellipsoids at the 30% probability level.
	Fig. 2. The molecular structure of the title para-Diels–Alder adduct (II), with displacement ellipsoids at the 30% probability level.
	Fig. 3. The supramolecular structure of the title ortho-Diels–Alder adduct (I), viewed along the c axis. [Symmetry codes: (i) −x, −y, 1 − z; (ii) 1/2 − x, 1/2 + y, 1/2 − z.]
	Fig. 4. The supramolecular structure of the title para-Diels–Alder adduct (II), viewed along the b axis. [Symmetry codes: (iii) x, 1 + y, z; (iv) x, 3/2 − y, 1/2 + z; (v) x, 3/2 − y, 1/2 + z; (vi) x, 5/2 − y, −1/2 + z.] [Codes iv and v are the same.]

(I) 2-(1,3-dioxo-2,3,3a,4,7,7a-hexahydro-1H-isoindol-2-yl)phenyl acetate

Crystal data

C16H15NO4	F(000) = 600
Mr = 285.30	Dx = 1.360 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 24 reflections
a = 9.6673 (7) Å	θ = 10–11°
b = 9.6787 (7) Å	µ = 0.10 mm^−1
c = 15.5880 (18) Å	T = 293 K
β = 107.131 (2)°	Block, colorless
V = 1393.8 (2) Å^3	0.40 × 0.30 × 0.20 mm
Z = 4

Data collection

Enraf–Nonius CAD-4 diffractometer	1861 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.018
Graphite monochromator	θmax = 28.0°, θmin = 2.2°
Detector resolution: 3 pixels mm^-1	h = −12→0
ω/2θ scans	k = 0→12
3470 measured reflections	l = −19→20
3291 independent reflections

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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.145	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0644P)^2 + 0.0798P] where P = (Fo^2 + 2Fc^2)/3
3291 reflections	(Δ/σ)max < 0.001
190 parameters	Δρmax = 0.19 e Å^−3
0 restraints	Δρmin = −0.19 e Å^−3

Special details

Experimental. Diffractometer operator Susana Rojas Lima scanwidth_degrees 0.7 low_scanspeed_degrees/min 16.1 high_scanspeed_degrees/min 60 Background measurement: Moving crystal and moving counter at the beginning and end of scan, each for 25% of total scan area. Crystal mounted on a glass fiber.

Melting points were measured on a Gallen–Kamp MFB-595 apparatus and are uncorrected. IR spectra were recorded as KBr discs using a Perkin–Elmer 16 F PC IR spectrophotometer. ¹H and ¹³C NMR spectra were recorded using a Jeol Eclipse spectrometer (¹H, 270.17; ¹³C, 67.94 MHz) in CDCl₃ solutions, (SiMe₄ as internal reference). Mass spectra were recorded on a Hewlett Packard 5989 A Series II spectrometer.

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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	0.55936 (14)	0.33488 (17)	0.55129 (9)	0.0620 (5)
O3	0.07218 (15)	0.32484 (17)	0.42650 (10)	0.0676 (5)
O14	0.33007 (13)	0.02698 (13)	0.49051 (7)	0.0469 (4)
O15	0.12026 (16)	−0.07623 (19)	0.41869 (10)	0.0766 (6)
N2	0.31988 (15)	0.31031 (14)	0.47415 (9)	0.0393 (4)
C1	0.43448 (19)	0.35858 (18)	0.54445 (12)	0.0430 (5)
C3	0.18586 (18)	0.35293 (18)	0.48060 (12)	0.0429 (5)
C3A	0.2091 (2)	0.43737 (18)	0.56519 (12)	0.0462 (6)
C4	0.1285 (2)	0.3735 (2)	0.62686 (14)	0.0578 (7)
C5	0.2086 (3)	0.2541 (2)	0.67797 (15)	0.0634 (8)
C6	0.3485 (3)	0.2616 (3)	0.71395 (14)	0.0659 (8)
C7	0.4300 (3)	0.3886 (3)	0.70302 (13)	0.0642 (7)
C7A	0.3741 (2)	0.44307 (18)	0.60651 (12)	0.0475 (6)
C8	0.33770 (18)	0.22604 (17)	0.40252 (11)	0.0375 (5)
C9	0.34090 (18)	0.08391 (17)	0.41081 (11)	0.0392 (5)
C10	0.36327 (19)	0.0019 (2)	0.34332 (12)	0.0487 (6)
C11	0.3795 (2)	0.0636 (2)	0.26696 (12)	0.0531 (6)
C12	0.3739 (2)	0.2054 (2)	0.25753 (12)	0.0527 (6)
C13	0.35428 (19)	0.2864 (2)	0.32569 (12)	0.0459 (5)
C15	0.2146 (2)	−0.0571 (2)	0.48639 (12)	0.0481 (6)
C16	0.2282 (3)	−0.1181 (2)	0.57601 (15)	0.0700 (8)
H3A	0.17261	0.53118	0.54890	0.0554*
H4A	0.11550	0.44303	0.66861	0.0693*
H4B	0.03338	0.34322	0.59098	0.0693*
H5	0.15911	0.17412	0.68430	0.0761*
H6	0.39809	0.18729	0.74676	0.0791*
H7A	0.40597	0.53901	0.60548	0.0570*
H7B	0.53228	0.36716	0.71698	0.0771*
H7C	0.41848	0.45924	0.74451	0.0771*
H10	0.36735	−0.09373	0.34934	0.0584*
H11	0.39426	0.00898	0.22138	0.0636*
H12	0.38342	0.24605	0.20550	0.0632*
H13	0.35215	0.38208	0.32003	0.0551*
H16A	0.14604	−0.17604	0.57232	0.1050*
H16B	0.23227	−0.04550	0.61862	0.1050*
H16C	0.31512	−0.17230	0.59496	0.1050*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0360 (7)	0.0903 (11)	0.0571 (8)	−0.0027 (7)	0.0098 (6)	−0.0093 (8)
O3	0.0387 (8)	0.0933 (11)	0.0648 (9)	0.0015 (8)	0.0058 (7)	−0.0170 (8)
O14	0.0522 (7)	0.0489 (7)	0.0369 (6)	−0.0129 (6)	0.0089 (5)	0.0039 (5)
O15	0.0600 (10)	0.1109 (13)	0.0558 (9)	−0.0327 (9)	0.0123 (8)	−0.0044 (8)
N2	0.0344 (7)	0.0424 (7)	0.0404 (7)	−0.0025 (6)	0.0099 (6)	−0.0017 (6)
C1	0.0386 (9)	0.0469 (9)	0.0423 (9)	−0.0063 (8)	0.0103 (7)	0.0011 (7)
C3	0.0366 (9)	0.0438 (9)	0.0477 (10)	0.0013 (7)	0.0115 (8)	0.0029 (7)
C3A	0.0473 (10)	0.0404 (9)	0.0523 (10)	0.0059 (8)	0.0170 (8)	−0.0005 (8)
C4	0.0501 (11)	0.0724 (14)	0.0571 (12)	0.0057 (10)	0.0255 (9)	−0.0012 (10)
C5	0.0718 (15)	0.0657 (13)	0.0635 (13)	−0.0013 (12)	0.0365 (12)	0.0074 (10)
C6	0.0775 (16)	0.0774 (14)	0.0472 (11)	0.0214 (13)	0.0252 (11)	0.0172 (10)
C7	0.0551 (12)	0.0916 (16)	0.0420 (10)	−0.0002 (12)	0.0083 (9)	−0.0154 (10)
C7A	0.0506 (10)	0.0430 (9)	0.0488 (10)	−0.0082 (8)	0.0145 (8)	−0.0086 (8)
C8	0.0324 (8)	0.0442 (9)	0.0354 (8)	−0.0027 (7)	0.0094 (6)	0.0006 (7)
C9	0.0372 (8)	0.0455 (9)	0.0333 (8)	−0.0031 (7)	0.0078 (7)	0.0028 (7)
C10	0.0460 (10)	0.0495 (10)	0.0492 (10)	−0.0032 (9)	0.0119 (8)	−0.0071 (9)
C11	0.0470 (10)	0.0710 (13)	0.0454 (10)	−0.0054 (10)	0.0202 (8)	−0.0110 (9)
C12	0.0457 (10)	0.0767 (14)	0.0389 (9)	−0.0050 (10)	0.0173 (8)	0.0078 (9)
C13	0.0398 (9)	0.0512 (10)	0.0461 (9)	−0.0018 (8)	0.0118 (8)	0.0092 (8)
C15	0.0517 (10)	0.0480 (10)	0.0473 (10)	−0.0093 (9)	0.0186 (8)	−0.0051 (8)
C16	0.0831 (16)	0.0705 (14)	0.0595 (13)	−0.0222 (12)	0.0259 (11)	0.0110 (11)

Geometric parameters (Å, º)

O1—C1	1.202 (2)	C10—C11	1.381 (3)
O3—C3	1.203 (2)	C11—C12	1.380 (3)
O14—C9	1.391 (2)	C12—C13	1.378 (3)
O14—C15	1.368 (2)	C15—C16	1.486 (3)
O15—C15	1.189 (2)	C3A—H3A	0.98
N2—C1	1.390 (2)	C4—H4A	0.97
N2—C3	1.391 (2)	C4—H4B	0.97
N2—C8	1.434 (2)	C5—H5	0.93
C1—C7A	1.509 (3)	C6—H6	0.93
C3—C3A	1.511 (3)	C7—H7B	0.97
C3A—C4	1.535 (3)	C7—H7C	0.97
C3A—C7A	1.535 (3)	C7A—H7A	0.98
C4—C5	1.485 (3)	C10—H10	0.93
C5—C6	1.305 (4)	C11—H11	0.93
C6—C7	1.497 (4)	C12—H12	0.93
C7—C7A	1.534 (3)	C13—H13	0.93
C8—C9	1.381 (2)	C16—H16A	0.96
C8—C13	1.384 (2)	C16—H16B	0.96
C9—C10	1.385 (2)	C16—H16C	0.96
O1···C1^i	3.330 (2)	C10···H13^vi	3.01
O14···C9^ii	3.279 (2)	C11···H13^vi	2.86
O14···C1	3.395 (2)	C13···H7A^i	2.81
O14···C10^ii	3.325 (2)	C15···H10	2.95
O14···N2	2.7532 (19)	H3A···O3^v	2.87
O15···C10	3.016 (3)	H4A···C7	2.97
O1···H7B	2.69	H4A···H11^viii	2.55
O1···H7A^i	2.84	H4B···O3	2.70
O1···H10^ii	2.78	H5···H16B	2.55
O3···H16A^iii	2.56	H5···H7C^ix	2.57
O3···H6^iv	2.81	H5···O15^iii	2.87
O3···H4B	2.70	H6···O3^x	2.81
O3···H3A^v	2.87	H7A···O1^i	2.84
O15···H10	2.90	H7A···C13^i	2.81
O15···H12^vi	2.58	H7A···H13^i	2.41
O15···H5^iii	2.87	H7B···O1	2.69
N2···O14	2.7532 (19)	H7C···C4	2.98
C1···O14	3.395 (2)	H7C···H5^xi	2.57
C1···C5	3.578 (3)	H10···O15	2.90
C1···O1^i	3.330 (2)	H10···C15	2.95
C1···C1^i	3.472 (3)	H10···O1^ii	2.78
C5···C1	3.578 (3)	H11···H13^vi	2.59
C9···O14^ii	3.279 (2)	H11···H4A^xii	2.55
C10···C13^vi	3.529 (3)	H12···O15^vii	2.58
C10···O15	3.016 (3)	H13···C10^vii	3.01
C10···O14^ii	3.325 (2)	H13···C11^vii	2.86
C11···C13^vi	3.531 (3)	H13···H11^vii	2.59
C13···C11^vii	3.531 (3)	H13···C7A^i	3.06
C13···C10^vii	3.529 (3)	H13···H7A^i	2.41
C4···H7C	2.98	H16A···O3^iii	2.56
C5···H16B	3.07	H16B···C5	3.07
C7···H4A	2.97	H16B···H5	2.55
C7A···H13^i	3.06
C9—O14—C15	117.97 (13)	C4—C3A—H3A	109
C1—N2—C3	112.73 (14)	C7A—C3A—H3A	109
C1—N2—C8	123.69 (15)	C3A—C4—H4A	109
C3—N2—C8	123.58 (14)	C3A—C4—H4B	109
O1—C1—N2	123.52 (17)	C5—C4—H4A	109
O1—C1—C7A	127.90 (17)	C5—C4—H4B	109
N2—C1—C7A	108.58 (16)	H4A—C4—H4B	108
O3—C3—N2	124.08 (17)	C4—C5—H5	120
O3—C3—C3A	127.19 (17)	C6—C5—H5	120
N2—C3—C3A	108.74 (15)	C5—C6—H6	120
C3—C3A—C4	110.88 (15)	C7—C6—H6	120
C3—C3A—C7A	104.75 (15)	C6—C7—H7B	110
C4—C3A—C7A	114.09 (15)	C6—C7—H7C	110
C3A—C4—C5	111.64 (18)	C7A—C7—H7B	110
C4—C5—C6	119.9 (2)	C7A—C7—H7C	110
C5—C6—C7	120.7 (2)	H7B—C7—H7C	108
C6—C7—C7A	110.40 (19)	C1—C7A—H7A	109
C1—C7A—C3A	105.18 (15)	C3A—C7A—H7A	109
C1—C7A—C7	110.57 (17)	C7—C7A—H7A	109
C3A—C7A—C7	114.92 (18)	C9—C10—H10	120
N2—C8—C9	119.89 (15)	C11—C10—H10	120
N2—C8—C13	120.34 (15)	C10—C11—H11	120
C9—C8—C13	119.76 (16)	C12—C11—H11	120
O14—C9—C8	118.20 (15)	C11—C12—H12	120
O14—C9—C10	121.41 (15)	C13—C12—H12	120
C8—C9—C10	120.27 (16)	C8—C13—H13	120
C9—C10—C11	119.32 (17)	C12—C13—H13	120
C10—C11—C12	120.73 (17)	C15—C16—H16A	109
C11—C12—C13	119.60 (17)	C15—C16—H16B	110
C8—C13—C12	120.31 (17)	C15—C16—H16C	109
O14—C15—O15	122.45 (17)	H16A—C16—H16B	109
O14—C15—C16	110.32 (17)	H16A—C16—H16C	109
O15—C15—C16	127.2 (2)	H16B—C16—H16C	109
C3—C3A—H3A	109
C15—O14—C9—C10	−65.5 (2)	N2—C3—C3A—C7A	1.67 (18)
C9—O14—C15—C16	174.85 (16)	C3—C3A—C7A—C7	−123.30 (18)
C15—O14—C9—C8	118.48 (18)	C3—C3A—C7A—C1	−1.47 (18)
C9—O14—C15—O15	−4.5 (3)	C4—C3A—C7A—C7	−1.9 (2)
C3—N2—C1—C7A	0.26 (19)	C7A—C3A—C4—C5	−38.9 (2)
C1—N2—C8—C9	89.5 (2)	C3—C3A—C4—C5	79.1 (2)
C8—N2—C1—C7A	−179.92 (15)	C4—C3A—C7A—C1	119.96 (16)
C8—N2—C1—O1	0.6 (3)	C3A—C4—C5—C6	42.9 (3)
C1—N2—C3—O3	178.94 (18)	C4—C5—C6—C7	−1.1 (3)
C8—N2—C3—O3	−0.9 (3)	C5—C6—C7—C7A	−41.7 (3)
C8—N2—C3—C3A	178.93 (14)	C6—C7—C7A—C1	−78.3 (3)
C3—N2—C1—O1	−179.25 (17)	C6—C7—C7A—C3A	40.6 (3)
C3—N2—C8—C13	90.5 (2)	C13—C8—C9—O14	177.31 (16)
C1—N2—C3—C3A	−1.25 (19)	C9—C8—C13—C12	0.0 (3)
C3—N2—C8—C9	−90.7 (2)	C13—C8—C9—C10	1.2 (3)
C1—N2—C8—C13	−89.3 (2)	N2—C8—C9—C10	−177.68 (16)
O1—C1—C7A—C3A	−179.71 (19)	N2—C8—C9—O14	−1.6 (3)
N2—C1—C7A—C3A	0.81 (18)	N2—C8—C13—C12	178.88 (17)
O1—C1—C7A—C7	−55.1 (3)	C8—C9—C10—C11	−1.3 (3)
N2—C1—C7A—C7	125.43 (18)	O14—C9—C10—C11	−177.25 (17)
N2—C3—C3A—C4	−121.85 (16)	C9—C10—C11—C12	0.1 (3)
O3—C3—C3A—C7A	−178.53 (18)	C10—C11—C12—C13	1.1 (3)
O3—C3—C3A—C4	58.0 (3)	C11—C12—C13—C8	−1.1 (3)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y, −z+1; (iii) −x, −y, −z+1; (iv) x−1/2, −y+1/2, z−1/2; (v) −x, −y+1, −z+1; (vi) −x+1/2, y−1/2, −z+1/2; (vii) −x+1/2, y+1/2, −z+1/2; (viii) x−1/2, −y+1/2, z+1/2; (ix) −x+1/2, y−1/2, −z+3/2; (x) x+1/2, −y+1/2, z+1/2; (xi) −x+1/2, y+1/2, −z+3/2; (xii) x+1/2, −y+1/2, z−1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C16—H16A···O3^iii	0.96	2.56	3.517 (3)	176
C12—H12···O15^vii	0.93	2.58	3.480 (3)	162

Symmetry codes: (iii) −x, −y, −z+1; (vii) −x+1/2, y+1/2, −z+1/2.

(II) 4-(1,3-dioxo-2,3,3a,4,7,7a-hexahydro-1H-isoindol-2-yl)phenyl acetate

Crystal data

C16H15NO4	F(000) = 600
Mr = 285.17	Dx = 1.314 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 24 reflections
a = 16.163 (1) Å	θ = 10–11°
b = 6.578 (1) Å	µ = 0.10 mm^−1
c = 13.583 (1) Å	T = 293 K
β = 93.73 (2)°	Block, colorless
V = 1441.1 (3) Å^3	0.20 × 0.15 × 0.09 mm
Z = 4

Data collection

Enraf–Nonius CAD-4 diffractometer	2056 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.020
Graphite monochromator	θmax = 28.0°, θmin = 2.5°
Detector resolution: 3 pixels mm^-1	h = 0→21
ω/2θ scans	k = −8→0
3450 measured reflections	l = −17→17
3450 independent reflections

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)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.182	H-atom parameters constrained
S = 1.14	w = 1/[σ^2(Fo^2) + (0.0946P)^2 + 0.0607P] where P = (Fo^2 + 2Fc^2)/3
3450 reflections	(Δ/σ)max = 0.001
191 parameters	Δρmax = 0.43 e Å^−3
0 restraints	Δρmin = −0.20 e Å^−3

Special details

Experimental. Diffractometer operator Susana Rojas Lima scanwidth_degrees 0.7 low_scanspeed_degrees/min 16.1 high_scanspeed_degrees/min 60 Background measurement: Moving crystal and moving counter at the beginning and end of scan, each for 25% of total scan area. Crystal mounted on a glass fiber.

Melting points were measured on a Gallen–Kamp MFB-595 apparatus and are uncorrected. IR spectra were recorded as KBr discs using a Perkin–Elmer 16 F PC IR spectrophotometer. ¹H and ¹³C NMR spectra were recorded using a Jeol Eclipse spectrometer (¹H, 270.17; ¹³C, 67.94 MHz) in CDCl₃ solutions, (SiMe₄ as internal reference). Mass spectra were recorded on a Hewlett Packard 5989 A Series II spectrometer.

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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	0.24578 (12)	1.0321 (3)	0.36249 (11)	0.0745 (6)
O3	0.32688 (9)	0.5160 (2)	0.16956 (10)	0.0545 (5)
O14	0.09535 (9)	1.1923 (2)	−0.05900 (10)	0.0594 (5)
O15	0.13805 (12)	1.0021 (3)	−0.18105 (12)	0.0783 (7)
N2	0.27355 (9)	0.7906 (2)	0.24784 (10)	0.0373 (4)
C1	0.27588 (12)	0.8706 (3)	0.34267 (12)	0.0440 (5)
C3	0.31379 (11)	0.6035 (3)	0.24479 (13)	0.0379 (5)
C3A	0.33652 (11)	0.5372 (3)	0.34991 (13)	0.0415 (5)
C4	0.42418 (13)	0.4502 (4)	0.36141 (17)	0.0595 (8)
C5	0.48488 (14)	0.6157 (5)	0.35188 (17)	0.0714 (9)
C6	0.47444 (15)	0.7922 (5)	0.39272 (17)	0.0712 (9)
C7	0.40345 (15)	0.8269 (4)	0.45524 (16)	0.0664 (8)
C7A	0.32243 (11)	0.7265 (3)	0.41193 (12)	0.0446 (6)
C8	0.23068 (10)	0.8862 (3)	0.16447 (12)	0.0369 (5)
C9	0.16453 (11)	0.7883 (3)	0.11522 (13)	0.0449 (6)
C10	0.12072 (12)	0.8847 (3)	0.03805 (14)	0.0496 (6)
C11	0.14337 (11)	1.0790 (3)	0.01249 (13)	0.0451 (6)
C12	0.21008 (12)	1.1761 (3)	0.05959 (14)	0.0470 (6)
C13	0.25389 (12)	1.0786 (3)	0.13636 (13)	0.0431 (5)
C15	0.10087 (12)	1.1449 (4)	−0.15435 (15)	0.0535 (7)
C16	0.05530 (15)	1.2987 (4)	−0.21816 (18)	0.0721 (9)
H3A	0.29744	0.43167	0.36789	0.0499*
H4B	0.43314	0.38597	0.42549	0.0715*
H4C	0.43126	0.34819	0.31110	0.0715*
H5	0.53125	0.59349	0.31620	0.0856*
H6	0.51153	0.89718	0.38276	0.0852*
H7A	0.28764	0.69095	0.46583	0.0535*
H7B	0.39453	0.97201	0.46174	0.0796*
H7C	0.41714	0.77245	0.52064	0.0796*
H9	0.14962	0.65812	0.13401	0.0539*
H10	0.07660	0.81969	0.00380	0.0595*
H12	0.22543	1.30548	0.04003	0.0565*
H13	0.29904	1.14239	0.16916	0.0518*
H16A	0.05464	1.25628	−0.28583	0.1082*
H16B	0.08257	1.42792	−0.21080	0.1082*
H16C	−0.00058	1.31050	−0.19883	0.1082*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.1075 (14)	0.0669 (10)	0.0478 (8)	0.0385 (10)	−0.0045 (8)	−0.0153 (7)
O3	0.0727 (10)	0.0433 (7)	0.0467 (8)	0.0079 (7)	−0.0017 (7)	−0.0113 (6)
O14	0.0565 (9)	0.0715 (10)	0.0496 (8)	0.0167 (8)	−0.0017 (6)	0.0110 (7)
O15	0.0840 (12)	0.0933 (13)	0.0561 (10)	0.0261 (10)	−0.0074 (8)	−0.0125 (9)
N2	0.0447 (8)	0.0345 (7)	0.0323 (7)	0.0015 (6)	−0.0007 (5)	0.0001 (5)
C1	0.0523 (10)	0.0451 (10)	0.0346 (8)	0.0066 (8)	0.0019 (7)	−0.0043 (7)
C3	0.0430 (9)	0.0306 (8)	0.0397 (8)	−0.0045 (7)	0.0003 (7)	−0.0013 (7)
C3A	0.0439 (10)	0.0374 (9)	0.0430 (9)	−0.0027 (8)	0.0003 (7)	0.0064 (7)
C4	0.0587 (13)	0.0656 (14)	0.0536 (12)	0.0191 (11)	−0.0019 (9)	0.0069 (10)
C5	0.0415 (11)	0.120 (2)	0.0523 (12)	−0.0006 (14)	0.0002 (9)	0.0062 (14)
C6	0.0579 (14)	0.097 (2)	0.0564 (13)	−0.0329 (14)	−0.0130 (10)	0.0133 (13)
C7	0.0812 (16)	0.0655 (14)	0.0490 (11)	0.0009 (12)	−0.0214 (10)	−0.0095 (10)
C7A	0.0495 (10)	0.0515 (11)	0.0329 (8)	0.0038 (8)	0.0038 (7)	0.0035 (8)
C8	0.0406 (9)	0.0367 (8)	0.0333 (7)	0.0029 (7)	0.0017 (6)	0.0008 (7)
C9	0.0460 (10)	0.0430 (10)	0.0456 (9)	−0.0090 (8)	0.0012 (7)	0.0062 (8)
C10	0.0413 (9)	0.0596 (12)	0.0467 (10)	−0.0087 (9)	−0.0059 (8)	0.0054 (9)
C11	0.0427 (10)	0.0531 (11)	0.0393 (9)	0.0084 (8)	0.0023 (7)	0.0064 (8)
C12	0.0548 (11)	0.0402 (10)	0.0461 (10)	−0.0006 (9)	0.0031 (8)	0.0052 (8)
C13	0.0487 (10)	0.0372 (9)	0.0426 (9)	−0.0034 (8)	−0.0033 (8)	0.0008 (7)
C15	0.0419 (10)	0.0687 (14)	0.0492 (10)	−0.0001 (10)	−0.0024 (8)	0.0066 (10)
C16	0.0602 (14)	0.0900 (18)	0.0643 (14)	0.0033 (13)	−0.0100 (10)	0.0289 (13)

Geometric parameters (Å, º)

O1—C1	1.206 (3)	C10—C11	1.380 (3)
O3—C3	1.204 (2)	C11—C12	1.375 (3)
O14—C11	1.415 (2)	C12—C13	1.380 (3)
O14—C15	1.341 (2)	C15—C16	1.495 (3)
O15—C15	1.185 (3)	C3A—H3A	0.98
N2—C1	1.390 (2)	C4—H4B	0.97
N2—C3	1.394 (2)	C4—H4C	0.97
N2—C8	1.434 (2)	C5—H5	0.93
C1—C7A	1.503 (3)	C6—H6	0.93
C3—C3A	1.515 (3)	C7—H7B	0.97
C3A—C4	1.527 (3)	C7—H7C	0.97
C3A—C7A	1.529 (3)	C7A—H7A	0.98
C4—C5	1.477 (4)	C9—H9	0.93
C5—C6	1.302 (4)	C10—H10	0.93
C6—C7	1.489 (3)	C12—H12	0.93
C7—C7A	1.548 (3)	C13—H13	0.93
C8—C9	1.383 (3)	C16—H16A	0.96
C8—C13	1.381 (3)	C16—H16B	0.96
C9—C10	1.381 (3)	C16—H16C	0.96
O1···C13	3.098 (2)	C1···H13	3.00
O1···C12^i	3.374 (3)	C3···H9	2.99
O1···C15^i	3.160 (3)	C4···H7C	3.04
O1···C16^i	3.388 (3)	C5···H4C^viii	3.08
O3···C7^ii	3.398 (3)	C6···H4B^ix	3.04
O3···C9	3.223 (2)	C7···H4B	2.97
O3···C12^iii	3.229 (2)	C8···H7A^ii	2.95
O3···C13^iii	3.131 (2)	C9···H16C^x	3.02
O15···C9^ii	3.412 (3)	C9···H7A^ii	2.94
O15···C10	3.105 (3)	C10···H7A^ii	2.97
O15···N2^ii	3.116 (2)	C11···H7A^ii	3.03
O15···C3A^ii	3.219 (3)	C12···H7A^ii	3.04
O15···C1^ii	3.314 (3)	C13···H7A^ii	3.00
O15···C3^ii	3.152 (3)	C15···H10	3.07
O1···H16B^i	2.77	H3A···O1^iii	2.76
O1···H12^i	2.68	H3A···O15^vi	2.65
O1···H3A^iv	2.76	H4B···C7	2.97
O1···H7B	2.71	H4B···C6^ix	3.04
O1···H13	2.91	H4C···O3	2.71
O3···H4C	2.71	H4C···C5^v	3.08
O3···H12^iii	2.71	H4C···H5^v	2.51
O3···H13^iii	2.50	H5···H4C^viii	2.51
O3···H6^v	2.86	H6···O3^viii	2.86
O15···H3A^ii	2.65	H7A···C8^vi	2.95
O15···H9^ii	2.74	H7A···C9^vi	2.94
N2···O15^vi	3.116 (2)	H7A···C10^vi	2.97
C1···O15^vi	3.314 (3)	H7A···C11^vi	3.03
C3···C6	3.412 (3)	H7A···C12^vi	3.04
C3···O15^vi	3.152 (3)	H7A···C13^vi	3.00
C3A···O15^vi	3.219 (3)	H7B···O1	2.71
C6···C3	3.412 (3)	H7C···C4	3.04
C7···O3^vi	3.398 (3)	H9···C3	2.99
C9···O15^vi	3.412 (3)	H9···O15^vi	2.74
C9···O3	3.223 (2)	H10···C15	3.07
C10···O15	3.105 (3)	H12···O3^iv	2.71
C12···O1^vii	3.374 (3)	H12···O1^vii	2.68
C12···O3^iv	3.229 (2)	H13···O1	2.91
C13···O3^iv	3.131 (2)	H13···O3^iv	2.50
C13···O1	3.098 (2)	H13···C1	3.00
C15···O1^vii	3.160 (3)	H16B···O1^vii	2.77
C16···O1^vii	3.388 (3)	H16C···C9^x	3.02
C11—O14—C15	118.19 (16)	C4—C3A—H3A	109
C1—N2—C3	112.17 (14)	C7A—C3A—H3A	109
C1—N2—C8	123.27 (15)	C3A—C4—H4B	110
C3—N2—C8	124.49 (14)	C3A—C4—H4C	110
O1—C1—N2	123.60 (17)	C5—C4—H4B	110
O1—C1—C7A	127.50 (16)	C5—C4—H4C	110
N2—C1—C7A	108.89 (15)	H4B—C4—H4C	108
O3—C3—N2	123.76 (17)	C4—C5—H5	119
O3—C3—C3A	128.12 (18)	C6—C5—H5	120
N2—C3—C3A	108.13 (15)	C5—C6—H6	120
C3—C3A—C4	111.77 (16)	C7—C6—H6	120
C3—C3A—C7A	104.43 (15)	C6—C7—H7B	109
C4—C3A—C7A	114.80 (16)	C6—C7—H7C	109
C3A—C4—C5	109.4 (2)	C7A—C7—H7B	109
C4—C5—C6	121.0 (2)	C7A—C7—H7C	109
C5—C6—C7	120.4 (3)	H7B—C7—H7C	108
C6—C7—C7A	112.46 (19)	C1—C7A—H7A	109
C1—C7A—C3A	104.79 (14)	C3A—C7A—H7A	109
C1—C7A—C7	110.21 (17)	C7—C7A—H7A	109
C3A—C7A—C7	113.84 (16)	C8—C9—H9	120
N2—C8—C9	119.77 (17)	C10—C9—H9	120
N2—C8—C13	119.63 (15)	C9—C10—H10	120
C9—C8—C13	120.56 (17)	C11—C10—H10	120
C8—C9—C10	119.71 (18)	C11—C12—H12	121
C9—C10—C11	119.02 (18)	C13—C12—H12	121
O14—C11—C10	121.18 (16)	C8—C13—H13	120
O14—C11—C12	116.95 (17)	C12—C13—H13	120
C10—C11—C12	121.74 (18)	C15—C16—H16A	109
C11—C12—C13	118.95 (18)	C15—C16—H16B	109
C8—C13—C12	119.98 (17)	C15—C16—H16C	109
O14—C15—O15	123.2 (2)	H16A—C16—H16B	109
O14—C15—C16	110.0 (2)	H16A—C16—H16C	109
O15—C15—C16	126.9 (2)	H16B—C16—H16C	109
C3—C3A—H3A	109
C15—O14—C11—C10	−76.1 (2)	N2—C3—C3A—C7A	−12.20 (19)
C15—O14—C11—C12	108.1 (2)	C3—C3A—C4—C5	70.2 (2)
C11—O14—C15—O15	6.9 (3)	C7A—C3A—C4—C5	−48.5 (2)
C11—O14—C15—C16	−172.12 (17)	C3—C3A—C7A—C1	11.94 (18)
C3—N2—C1—O1	179.2 (2)	C3—C3A—C7A—C7	−108.55 (17)
C3—N2—C1—C7A	0.3 (2)	C4—C3A—C7A—C1	134.67 (17)
C8—N2—C1—O1	−3.9 (3)	C4—C3A—C7A—C7	14.2 (2)
C8—N2—C1—C7A	177.27 (15)	C3A—C4—C5—C6	41.4 (3)
C1—N2—C3—O3	−172.18 (18)	C4—C5—C6—C7	3.8 (4)
C1—N2—C3—C3A	7.7 (2)	C5—C6—C7—C7A	−40.6 (3)
C8—N2—C3—O3	10.9 (3)	C6—C7—C7A—C1	−88.7 (2)
C8—N2—C3—C3A	−169.19 (15)	C6—C7—C7A—C3A	28.7 (3)
C1—N2—C8—C9	−116.7 (2)	N2—C8—C9—C10	176.80 (16)
C1—N2—C8—C13	60.9 (2)	C13—C8—C9—C10	−0.8 (3)
C3—N2—C8—C9	59.9 (2)	N2—C8—C13—C12	−176.48 (16)
C3—N2—C8—C13	−122.54 (19)	C9—C8—C13—C12	1.1 (3)
O1—C1—C7A—C3A	173.2 (2)	C8—C9—C10—C11	−0.9 (3)
O1—C1—C7A—C7	−63.9 (3)	C9—C10—C11—O14	−173.36 (17)
N2—C1—C7A—C3A	−8.0 (2)	C9—C10—C11—C12	2.3 (3)
N2—C1—C7A—C7	114.85 (17)	O14—C11—C12—C13	173.84 (17)
O3—C3—C3A—C4	43.0 (3)	C10—C11—C12—C13	−2.0 (3)
O3—C3—C3A—C7A	167.67 (19)	C11—C12—C13—C8	0.3 (3)
N2—C3—C3A—C4	−136.89 (17)

Symmetry codes: (i) x, −y+5/2, z+1/2; (ii) x, −y+3/2, z−1/2; (iii) x, y−1, z; (iv) x, y+1, z; (v) −x+1, y−1/2, −z+1/2; (vi) x, −y+3/2, z+1/2; (vii) x, −y+5/2, z−1/2; (viii) −x+1, y+1/2, −z+1/2; (ix) −x+1, −y+1, −z+1; (x) −x, −y+2, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C13—H13···O3^iv	0.93	2.50	3.131 (2)	125
C7A—H7A···Cg3^vi	0.98	2.65	3.611 (2)	167

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