Supramolecular aggregation of two hydroxy­carboxylic acid derivatives

The crystal structures of 7,7-dicyclo­but­yl-5-hydroxy­meth­yl-6-oxabicyclo­[3.2.1]octa­ne-1-carboxylic acid, C₁₇H₂₆O₄, (I), and 1-(hydroxy­meth­yl)-7-oxaspiro­[bicyclo­[3.2.1]octa­ne-6,1'-cyclo­penta­ne]-5-carboxylic acid, C₁₃H₂₀O₄, (II), determined at 170 K, show that the conformation of the hydroxy­meth­yl group (anti or gauche) affects the dimensionality (one- or two-dimensional) of the supramolecular structures via O-H...O hydrogen bonds. In (I), the carbox­yl and hydroxy­meth­yl groups inter­act with themselves, forming a one-dimensional step-ladder, while in (II), a two-dimensional structure is made up of carboxylic acid centrosymmetric R₂²(8) dimers connected by hydrox­yl-to-ether contacts.

S1. Comment

We have reported that compounds possessing axially oriented hydroxyl/carboxylic acid functions might create, by incorporation of water molecules, three-dimensional tubular structures in the crystalline state. Compounds (I) and (II) were considered to be promising candidates, since their respective homologues, (III) and (IV), have been shown to adopt hydrated tubular structures in the solid state (Carrasco et al., 2001). The crystal structures of compounds (I) and (II), reported in this paper, reveal a lack of hydration water molecules, although they were crystallized in a water-saturated atmosphere. To date, compound (IV) is the only one of this series which crystallizes in the anhydrous and hydrated forms in the absence or presence of water atmosphere, respectively.

The molecular structures of compounds (I) and (II) are displayed in Figs. 1 and 2, respectively. In (I), the cyclobutane rings are puckered (Table 1), with dihedral angles of 26.1 (2) (C13/C10/C11 and C11/C12/C13 planes) and 31.7 (1)° (C15/C14/C17 and C15/C16/C17 planes). The oxolane ring, in both compounds, presents a distorted ⁴T₅ half-chair toward an E₅ envelope conformation, according to the puckering parameters (Cremer & Pople, 1975) and the notation of Giacovazzo et al. (1992) for the C1/O1/C9/C5/C6 sequence [ϕ₂ = −50.1 (2) and −51.7 (1)°]. The cyclohexane presents a distorted ¹C₄ towards ¹E conformation [C6/C1/C2/C3/C4/C5; ϕ = 0.4 (3) and 1.8 (3)°, and θ = 27.0 (3) and 23.8 (1)°].

The molecules of (II) exhibit positional disorder in the cyclopentane ring and in the carboxylic acid group (Fig. 2). The cyclopentane ring adopts two conformations, namely ⁵T₄ and ⁵E for molecules A [ϕ₂ = 133.3 (6)°], and between ⁵T₁ and E₁ for molecules B [ϕ₂ = 173.9 (11)°], for the C9/C10/C11A/C11B/C12/C13 sequence. In the carboxylic acid group, the C—O distances and O—C—C angle are significantly different from those in (I) (Tables 1 and 3), although in good agreement with the values previously reported for the disordered group (Carrasco et al., 2001).

The O—H···O hydrogen-bonding motifs may be described as double-strand ladders in (I) and sheets in (II) (Figs. 3 and 4), which are closely related to the anti and gauche conformations of the hydroxyl group with respect to the oxolane bridge (Tables 1 and 3). As observed previously (Carrasco et al., 2001), the anti conformation gives one-dimensional assemblies, while a gauche conformation gives either one- or two-dimensional assemblies.

The supramolecular structure in (I) also differs from that in (II), in the absence of the centrosymmetric R₂²(8) motif (Tables 2 and 4). In (I), the carboxylic acid group acts as both a donor to the hydroxyl group, forming strands, and as an acceptor, joining two strands into a step-ladder structure (Nguyen et al., 2001) of alternating R₂²(16) and R₄⁴(12) motifs. Each strand (Fig. 3) contains only one enantiomer, related only by translation, whereas the step-ladder is formed by one strand of one handedness and one strand of opposite handedness, giving rise to an achiral ladder. A similar supramolecular structure is present in the anhydrous form of compound (IV) and in the homologues (V) and (VI) (Carrasco et al., 2001), which have two fewer C atoms. No other weak interactions, except van der Waals interactions, are observed between ladders (Fig. 5).

In compound (II), the H-atom disorder does not affect the supramolecular structure, since the carboxylic acid group interacts strongly with itself, forming the acid-to-acid hydrogen-bonding R₂²(8) motif (Leiserowitz, 1976; Etter, 1990; Bernstein et al., 1995). This dimeric association, linked by hydroxyl-to-ether hydrogen bonds, results in sheets (Fig. 4) that are further joined via C—H···O interactions into a three-dimensional network (Table 4 and dashed lines in Fig. 6). The formation of the R₂²(8) motif is prevented in the related analogues with two-dimensional structures (Carrasco et al., 2001).

Comparison with the previously reported hydroxy–acid analogues confirms that the relative positions of the hydroxyl and carboxylic acid groups, together with the molecular size, can lead to a range of hydrogen-bonded supramolecular structures with various dimensionalities. The reliability of the axially oriented hydroxyl/carboxylic acid functions in giving anhydrous layers reduces the design of the last remaining dimension to the incorporation of water molecules.

S2. Experimental

Compounds (I) and (II) were synthesized by condensing the dilithium salt of 3-methylenecyclohexanecarboxylic acid with, respectively, dicyclobutylmethanone (Erickson et al., 1966) or cyclopentanone, following the synthetic sequence reported for the other members of this family of compounds (Carrasco et al., 2001). Analysis for compound (I): m.p. 448–449 K; ¹H NMR (300 MHz, MeOD, δ, p.p.m.): 3.67 (d, J = 11.5 Hz, 1H), 3.62 (d, J = 11.5 Hz, 1H), 3.23 (m, 1H), 2.61 (m, 1H), 2.47 (d, J = 11.8 Hz, 1H), 2.27 (m, 3H), 2.12 (m, 2H), 1.99 (m, 3H), 1.74 (m, 8H), 1.58 (m, 2H), 1.40 (d, J = 11.8 Hz, 1H); ¹³C NMR (75.4 MHz, MeOD, δ, p.p.m.): 17.7, 18.1, 19.5, 26.2, 26.7, 27.4, 31.9, 32.8, 40.4, 41.1, 44.6, 47.6, 56.9, 67.3, 82.4, 86.4, 176.2; IR (KBr, ν_max, cm⁻¹): 3398, 2950, 2363, 1701, 1651, 1540, 1458, 1251, 1167, 1123, 995. Analysis for compound (II): m.p. 426–427 K; ¹H NMR (300 MHz, MeOD, δ, p.p.m.): 3.48 (d, J = 11.7 Hz, 1H), 3.42 (d, J = 11.7 Hz, 1H), 2.50 (d, J = 11.4 Hz, 1H), 2.20 (m, 2H), 1.95 (m, 2H), 1.73 (m, 5H), 1.59 (d, J = 11.4 Hz, 1H), 1.50 (m, 4H), 1.40 (dd, J₁ = 12.4, J₂ = 5.8 Hz, 1H); ¹³C NMR (75.4 MHz, MeOD, δ, p.p.m.): 19.7, 24.1, 24.5, 31.7, 31.8, 32.0, 39.2, 40.6, 55.6, 66.4, 82.3, 94.1, 176.0; IR (KBr, ν_max, cm⁻¹): 3749, 3380, 2956, 2870, 2361, 2337, 1703, 1456, 1339, 1257, 1157, 1046, 1002. Single crystals of (I) and (II), suitable for X-ray analysis, were grown at room temperature from a damp carbon tetrachloride–2,2,4-trimethylpentane mixture (Ratio?).

S3. Refinement

All H atoms were located in difference Fourier maps and subsequently allowed to refine as riding models on their respective C and O atoms, with C—H = 0.99 (CH₂) or 1.00 Å (CH) and O—H = 0.84 Å, and with U_iso(H) = 1.2U_eq(C, O). The molecules of (II) (Fig. 2) exhibit positional disorder in the carboxylic acid H atom [pp(H4) = 0.59 (3), pp(H3) = 0.41 (3)] and in the cyclopentane ring [pp(C11A) = 0.58 (2), pp(C11B) = 0.42 (2)]. The bond distances around the disordered atoms C11A/B (Fig. 2) in the cyclopentane ring were restrained using the DFIX command based on the average Csp³—Csp³ value (Allen et al., 1987). Attempted free refinement led to unrealistic geometrical parameters.

Computing details

For both compounds, data collection: KappaCCD Server Software (Nonius, 2000); cell refinement: HKL DENZO and SCALEPACK (Otwinowski & Minor 1997); data reduction: HKL DENZO and SCALEPACK; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Xtal3.6 (Hall et al., 1999) and PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97, WinGX (Farrugia, 1999) and PLATON.

Figures

	Fig. 1. The molecular structure of (I), with 30% probability displacement ellipsoids. H atoms are shown as spheres of arbitrary radii.
	Fig. 2. The molecular structure of (II), with 30% probability displacement ellipsoids. H atoms are shown as spheres of arbitrary radii. The disorder model in the cyclopentane ring and in the carboxylic group is represented by dashed lines.
	Fig. 3. The one-dimensional hydrogen-bonded step-ladders in (I), formed by hydroxyl-to-hydroxyl bonds (dotted lines). H atoms not involved in the hydrogen bonds have been omitted for clarity. [Symmetry codes: (i) x − 1, 1 + y, z; (ii) 1 − x, −y, −z.]
	Fig. 4. The two-dimensional hydrogen-bonded layer in (II), formed by molecules joined via a combination of acid-to-acid and hydroxyl-to-ether hydrogen bonds (dotted lines). H atoms not involved in the hydrogen bonds and the minor component of the disordered carboxylic acid group have been omitted for clarity. [Symmetry codes: (i) 1 − x, 1 − y, −z; (ii) −x, 1/2 + y, 1/2 − z; (iii) x, 1 + y, z; (iv) 1 − x, 2 − y, −z; (v) 1 + x, 3/2 − y, −1/2 + z.]
	Fig. 5. A packing diagram for (I), illustrating the disposition of two ladders running along the a axis. H atoms not involved in the hydrogen bonds have been omitted for clarity.
	Fig. 6. A packing diagram for (II), illustrating the disposition of the sheets. C—H···O interactions (dashed lines) link the sheets into a three-dimensional network. H atoms not involved in the hydrogen bonds and the minor component of the disordered carboxylic group have been omitted for clarity.

(I) 7,7-Dicyclobutyl-5-hydroxymethyl-6-oxabicyclo[3.2.1]octane-1-carboxylic acid

Crystal data

C17H26O4	Z = 2
Mr = 294.38	F(000) = 320
Triclinic, P1	Dx = 1.270 Mg m^−3
Hall symbol: -P 1	Melting point = 448–449 K
a = 8.757 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.807 (3) Å	Cell parameters from 3531 reflections
c = 11.769 (6) Å	θ = 1.8–27.5°
α = 84.073 (11)°	µ = 0.09 mm^−1
β = 75.766 (13)°	T = 170 K
γ = 61.044 (9)°	Prism, colourless
V = 769.7 (5) Å^3	0.45 × 0.10 × 0.10 mm

Data collection

Nonius KappaCCD area-detector diffractometer	3087 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.000
Horizontally mounted graphite crystal monochromator	θmax = 27.5°, θmin = 1.8°
Detector resolution: 9 pixels mm^-1	h = 0→11
ϕ and ω scans	k = −9→11
3531 measured reflections	l = −14→15
3531 independent reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.058	H-atom parameters constrained
wR(F^2) = 0.176	w = 1/[σ^2(Fo^2) + (0.1125P)^2 + 0.2845P] where P = (Fo^2 + 2Fc^2)/3
S = 1.03	(Δ/σ)max < 0.001
3531 reflections	Δρmax = 0.45 e Å^−3
191 parameters	Δρmin = −0.46 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.155 (15)

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	0.59693 (14)	0.05265 (14)	0.30781 (10)	0.0200 (3)
O2	0.92296 (16)	−0.30382 (17)	0.10000 (11)	0.0309 (3)
H2	0.8770	−0.3421	0.0636	0.037*
O3	0.29920 (19)	0.29624 (18)	0.02871 (13)	0.0386 (4)
O4	0.23644 (16)	0.51195 (16)	0.14536 (11)	0.0273 (3)
H4	0.1491	0.5655	0.1133	0.033*
C1	0.7211 (2)	−0.0218 (2)	0.19675 (14)	0.0212 (4)
C2	0.8680 (2)	0.0310 (2)	0.17486 (16)	0.0275 (4)
H2A	0.9478	−0.0129	0.0967	0.033*
H2B	0.9409	−0.0221	0.2344	0.033*
C3	0.7878 (2)	0.2285 (3)	0.18076 (17)	0.0297 (4)
H3A	0.8802	0.2605	0.1376	0.036*
H3B	0.7569	0.2650	0.2637	0.036*
C4	0.6200 (2)	0.3296 (2)	0.13016 (16)	0.0257 (4)
H4A	0.6576	0.3377	0.0442	0.031*
H4B	0.5516	0.4491	0.1635	0.031*
C5	0.4952 (2)	0.2454 (2)	0.15573 (14)	0.0201 (4)
C6	0.6079 (2)	0.0610 (2)	0.10563 (14)	0.0216 (4)
H6A	0.6824	0.0566	0.0264	0.026*
H6B	0.5331	0.0063	0.1030	0.026*
C7	0.3343 (2)	0.3519 (2)	0.10279 (14)	0.0227 (4)
C8	0.7969 (2)	−0.2171 (2)	0.20617 (15)	0.0253 (4)
H8A	0.8571	−0.2579	0.2726	0.030*
H8B	0.6980	−0.2465	0.2220	0.030*
C9	0.4385 (2)	0.2104 (2)	0.28944 (14)	0.0180 (3)
C10	0.4054 (2)	0.3516 (2)	0.37322 (14)	0.0199 (4)
H10	0.4928	0.3955	0.3394	0.024*
C11	0.2179 (2)	0.5105 (2)	0.41273 (15)	0.0247 (4)
H11A	0.2033	0.6177	0.3697	0.030*
H11B	0.1173	0.4879	0.4141	0.030*
C12	0.2589 (2)	0.5020 (2)	0.53405 (15)	0.0275 (4)
H12A	0.1597	0.5124	0.6006	0.033*
H12B	0.3032	0.5829	0.5443	0.033*
C13	0.4086 (2)	0.3133 (2)	0.50419 (15)	0.0239 (4)
H13A	0.3718	0.2246	0.5363	0.029*
H13B	0.5229	0.2873	0.5232	0.029*
C14	0.2765 (2)	0.1767 (2)	0.31482 (14)	0.0191 (4)
H14	0.1725	0.2844	0.2957	0.023*
C15	0.2119 (2)	0.1175 (2)	0.43764 (15)	0.0226 (4)
H15A	0.3098	0.0403	0.4772	0.027*
H15B	0.1147	0.2138	0.4905	0.027*
C16	0.1464 (2)	0.0212 (2)	0.37677 (17)	0.0287 (4)
H16A	0.0193	0.0899	0.3720	0.034*
H16B	0.1728	−0.0956	0.4081	0.034*
C17	0.2798 (2)	0.0194 (2)	0.26333 (16)	0.0265 (4)
H17A	0.2310	0.0459	0.1921	0.032*
H17B	0.3978	−0.0866	0.2516	0.032*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0165 (6)	0.0222 (6)	0.0162 (6)	−0.0054 (5)	−0.0031 (4)	0.0002 (4)
O2	0.0232 (6)	0.0342 (7)	0.0251 (7)	−0.0029 (6)	−0.0071 (5)	−0.0107 (5)
O3	0.0370 (8)	0.0336 (8)	0.0387 (8)	−0.0035 (6)	−0.0230 (7)	−0.0080 (6)
O4	0.0246 (6)	0.0240 (6)	0.0284 (7)	−0.0056 (5)	−0.0107 (5)	0.0005 (5)
C1	0.0163 (7)	0.0259 (8)	0.0159 (7)	−0.0060 (7)	−0.0020 (6)	−0.0022 (6)
C2	0.0184 (8)	0.0370 (10)	0.0238 (9)	−0.0107 (7)	−0.0041 (7)	−0.0004 (7)
C3	0.0235 (9)	0.0391 (10)	0.0304 (10)	−0.0190 (8)	−0.0034 (7)	0.0010 (8)
C4	0.0253 (9)	0.0303 (9)	0.0228 (8)	−0.0167 (7)	−0.0018 (7)	0.0048 (7)
C5	0.0197 (8)	0.0238 (8)	0.0158 (7)	−0.0100 (7)	−0.0035 (6)	0.0010 (6)
C6	0.0183 (7)	0.0251 (8)	0.0161 (8)	−0.0065 (7)	−0.0033 (6)	−0.0004 (6)
C7	0.0228 (8)	0.0253 (8)	0.0174 (8)	−0.0101 (7)	−0.0039 (6)	0.0019 (6)
C8	0.0211 (8)	0.0254 (9)	0.0212 (8)	−0.0039 (7)	−0.0057 (7)	−0.0022 (7)
C9	0.0143 (7)	0.0198 (8)	0.0176 (7)	−0.0063 (6)	−0.0040 (6)	0.0011 (6)
C10	0.0193 (8)	0.0216 (8)	0.0195 (8)	−0.0104 (7)	−0.0032 (6)	−0.0010 (6)
C11	0.0254 (9)	0.0221 (8)	0.0251 (9)	−0.0097 (7)	−0.0047 (7)	−0.0041 (7)
C12	0.0297 (9)	0.0291 (9)	0.0237 (9)	−0.0141 (8)	−0.0029 (7)	−0.0067 (7)
C13	0.0260 (8)	0.0271 (9)	0.0202 (8)	−0.0133 (7)	−0.0058 (7)	−0.0014 (6)
C14	0.0165 (7)	0.0206 (8)	0.0199 (8)	−0.0088 (6)	−0.0030 (6)	−0.0010 (6)
C15	0.0222 (8)	0.0255 (8)	0.0213 (8)	−0.0137 (7)	−0.0020 (6)	0.0004 (6)
C16	0.0280 (9)	0.0319 (9)	0.0313 (10)	−0.0195 (8)	−0.0028 (7)	−0.0018 (7)
C17	0.0262 (9)	0.0302 (9)	0.0280 (9)	−0.0175 (7)	−0.0024 (7)	−0.0063 (7)

Geometric parameters (Å, º)

O1—C1	1.452 (2)	C8—H8B	0.9900
O1—C9	1.4559 (18)	C9—C10	1.538 (2)
O2—C8	1.437 (2)	C9—C14	1.540 (2)
O2—H2	0.8400	C10—C13	1.548 (2)
O3—C7	1.209 (2)	C10—C11	1.551 (2)
O4—C7	1.318 (2)	C10—H10	1.0000
O4—H4	0.8400	C11—C12	1.542 (3)
C1—C8	1.517 (2)	C11—H11A	0.9900
C1—C6	1.525 (2)	C11—H11B	0.9900
C1—C2	1.527 (2)	C12—C13	1.545 (2)
C2—C3	1.530 (3)	C12—H12A	0.9900
C2—H2A	0.9900	C12—H12B	0.9900
C2—H2B	0.9900	C13—H13A	0.9900
C3—C4	1.537 (2)	C13—H13B	0.9900
C3—H3A	0.9900	C14—C17	1.553 (2)
C3—H3B	0.9900	C14—C15	1.552 (2)
C4—C5	1.552 (2)	C14—H14	1.0000
C4—H4A	0.9900	C15—C16	1.536 (2)
C4—H4B	0.9900	C15—H15A	0.9900
C5—C7	1.512 (2)	C15—H15B	0.9900
C5—C6	1.523 (2)	C16—C17	1.539 (3)
C5—C9	1.576 (2)	C16—H16A	0.9900
C6—H6A	0.9900	C16—H16B	0.9900
C6—H6B	0.9900	C17—H17A	0.9900
C8—H8A	0.9900	C17—H17B	0.9900
C1—O1—C9	110.78 (12)	O1—C9—C5	102.20 (12)
C8—O2—H2	109.5	C10—C9—C5	114.21 (13)
C7—O4—H4	109.5	C14—C9—C5	111.94 (12)
O1—C1—C8	106.61 (13)	C9—C10—C13	120.77 (14)
O1—C1—C6	104.38 (12)	C9—C10—C11	121.96 (13)
C8—C1—C6	114.91 (14)	C13—C10—C11	88.25 (12)
O1—C1—C2	109.48 (13)	C9—C10—H10	108.0
C8—C1—C2	111.58 (14)	C13—C10—H10	108.0
C6—C1—C2	109.49 (14)	C11—C10—H10	108.0
C1—C2—C3	110.99 (14)	C12—C11—C10	88.57 (13)
C1—C2—H2A	109.4	C12—C11—H11A	113.9
C3—C2—H2A	109.4	C10—C11—H11A	113.9
C1—C2—H2B	109.4	C12—C11—H11B	113.9
C3—C2—H2B	109.4	C10—C11—H11B	113.9
H2A—C2—H2B	108.0	H11A—C11—H11B	111.1
C2—C3—C4	114.51 (15)	C11—C12—C13	88.66 (13)
C2—C3—H3A	108.6	C11—C12—H12A	113.9
C4—C3—H3A	108.6	C13—C12—H12A	113.9
C2—C3—H3B	108.6	C11—C12—H12B	113.9
C4—C3—H3B	108.6	C13—C12—H12B	113.9
H3A—C3—H3B	107.6	H12A—C12—H12B	111.1
C3—C4—C5	113.42 (14)	C12—C13—C10	88.55 (12)
C3—C4—H4A	108.9	C12—C13—H13A	113.9
C5—C4—H4A	108.9	C10—C13—H13A	113.9
C3—C4—H4B	108.9	C12—C13—H13B	113.9
C5—C4—H4B	108.9	C10—C13—H13B	113.9
H4A—C4—H4B	107.7	H13A—C13—H13B	111.1
C7—C5—C6	112.72 (14)	C9—C14—C17	123.64 (13)
C7—C5—C4	110.09 (14)	C9—C14—C15	120.77 (13)
C6—C5—C4	106.73 (13)	C17—C14—C15	87.09 (13)
C7—C5—C9	111.74 (13)	C9—C14—H14	107.8
C6—C5—C9	101.15 (12)	C17—C14—H14	107.8
C4—C5—C9	114.07 (13)	C15—C14—H14	107.8
C5—C6—C1	99.49 (13)	C16—C15—C14	87.98 (13)
C5—C6—H6A	111.9	C16—C15—H15A	114.0
C1—C6—H6A	111.9	C14—C15—H15A	114.0
C5—C6—H6B	111.9	C16—C15—H15B	114.0
C1—C6—H6B	111.9	C14—C15—H15B	114.0
H6A—C6—H6B	109.6	H15A—C15—H15B	111.2
O3—C7—O4	123.40 (15)	C15—C16—C17	88.18 (13)
O3—C7—C5	123.5 (2)	C15—C16—H16A	114.0
O4—C7—C5	113.1 (1)	C17—C16—H16A	114.0
O2—C8—C1	111.04 (15)	C15—C16—H16B	114.0
O2—C8—H8A	109.4	C17—C16—H16B	114.0
C1—C8—H8A	109.4	H16A—C16—H16B	111.2
O2—C8—H8B	109.4	C16—C17—C14	87.86 (13)
C1—C8—H8B	109.4	C16—C17—H17A	114.0
H8A—C8—H8B	108.0	C14—C17—H17A	114.0
O1—C9—C10	107.66 (12)	C16—C17—H17B	114.0
O1—C9—C14	109.81 (12)	C14—C17—H17B	114.0
C10—C9—C14	110.57 (13)	H17A—C17—H17B	111.2
C9—O1—C1—C8	−140.50 (13)	C4—C5—C9—O1	−78.74 (15)
C9—O1—C1—C6	−18.48 (16)	C7—C5—C9—C10	−88.47 (16)
C9—O1—C1—C2	98.66 (14)	C6—C5—C9—C10	151.37 (13)
O1—C1—C2—C3	−55.16 (18)	C4—C5—C9—C10	37.20 (18)
C8—C1—C2—C3	−172.94 (14)	C7—C5—C9—C14	38.14 (18)
C6—C1—C2—C3	58.71 (18)	C6—C5—C9—C14	−82.02 (15)
C1—C2—C3—C4	−36.8 (2)	C4—C5—C9—C14	163.82 (13)
C2—C3—C4—C5	37.1 (2)	C14—C9—C10—C13	72.33 (17)
C3—C4—C5—C7	−179.77 (15)	C5—C9—C10—C13	−160.35 (14)
C3—C4—C5—C6	−57.12 (18)	O1—C9—C10—C11	−156.9 (1)
C3—C4—C5—C9	53.70 (19)	O1—C9—C10—C13	−47.6 (2)
C7—C5—C6—C1	−165.16 (13)	C14—C9—C10—C11	−36.9 (2)
C4—C5—C6—C1	73.85 (15)	C5—C9—C10—C11	90.41 (18)
C9—C5—C6—C1	−45.70 (15)	C9—C10—C11—C12	144.09 (15)
O1—C1—C6—C5	40.14 (15)	C13—C10—C11—C12	18.3 (1)
C8—C1—C6—C5	156.54 (14)	C10—C11—C12—C13	−18.4 (1)
C2—C1—C6—C5	−76.98 (15)	C11—C12—C13—C10	18.4 (1)
C6—C5—C7—O3	0.0 (2)	C11—C10—C13—C12	−18.3 (1)
C4—C5—C7—O3	119.07 (19)	C9—C10—C13—C12	−145.03 (15)
C9—C5—C7—O3	−113.10 (19)	C10—C9—C14—C17	−167.78 (15)
C6—C5—C7—O4	−179.78 (14)	C5—C9—C14—C17	63.66 (19)
C4—C5—C7—O4	−60.73 (18)	C10—C9—C14—C15	−58.81 (18)
C9—C5—C7—O4	67.10 (18)	C5—C9—C14—C15	172.63 (13)
O1—C1—C8—O2	−179.8 (1)	C9—C14—C15—C16	−150.16 (15)
C6—C1—C8—O2	65.11 (18)	O1—C9—C14—C15	59.9 (2)
C2—C1—C8—O2	−60.28 (18)	O1—C9—C14—C17	−49.1 (2)
C1—O1—C9—C10	−131.20 (13)	C17—C14—C15—C16	−22.2 (1)
C1—O1—C9—C14	108.37 (14)	C14—C15—C16—C17	22.4 (1)
C1—O1—C9—C5	−10.59 (15)	C15—C16—C17—C14	−22.4 (1)
C7—C5—C9—O1	155.58 (13)	C15—C14—C17—C16	22.2 (1)
C6—C5—C9—O1	35.42 (14)	C9—C14—C17—C16	147.70 (15)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O3^i	0.84	1.96	2.718 (2)	149
O4—H4···O2^ii	0.84	1.78	2.585 (2)	159

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

(II) 1-(hydroxymethyl)-7-oxaspiro[bicyclo[3.2.1]octane-6,1'-cyclopentane]-5- carboxylic acid

Crystal data

C13H20O4	F(000) = 520
Mr = 240.29	Dx = 1.325 Mg m^−3
Monoclinic, P21/c	Melting point = 426–427 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 10.850 (3) Å	Cell parameters from 2589 reflections
b = 7.050 (2) Å	θ = 1.9–27.0°
c = 15.790 (5) Å	µ = 0.10 mm^−1
β = 94.207 (10)°	T = 170 K
V = 1204.6 (6) Å^3	Sphere, colourless
Z = 4	0.50 × 0.50 × 0.45 × 0.48 (radius) mm

Data collection

Nonius KappaCCD diffractometer	2377 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.000
Horizontally mounted graphite crystal monochromator	θmax = 27.0°, θmin = 1.9°
Detector resolution: 9 pixels mm^-1	h = 0→13
ϕ and ω scans	k = 0→8
2589 measured reflections	l = −20→20
2589 independent reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.049	H-atom parameters constrained
wR(F^2) = 0.154	w = 1/[σ^2(Fo^2) + (0.111P)^2 + 0.2862P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max = 0.001
2589 reflections	Δρmax = 0.40 e Å^−3
169 parameters	Δρmin = −0.31 e Å^−3
4 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.20 (2)

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	Occ. (<1)
O1	0.13635 (8)	0.30263 (13)	0.21188 (5)	0.0167 (3)
O2	−0.03979 (10)	0.60592 (14)	0.15469 (7)	0.0257 (3)
H2	−0.0746	0.6534	0.1955	0.031*
O4	0.34127 (10)	0.53952 (16)	0.00803 (7)	0.0319 (3)
H4	0.4068	0.5750	−0.0124	0.038*	0.59 (3)
O3	0.46810 (10)	0.31811 (17)	0.06462 (8)	0.0354 (3)
H3	0.5168	0.3722	0.0334	0.042*	0.41 (3)
C1	0.05326 (11)	0.29888 (17)	0.13460 (8)	0.0153 (3)
C2	0.02615 (12)	0.09101 (18)	0.11289 (8)	0.0202 (3)
H2A	−0.0216	0.0829	0.0571	0.024*
H2B	−0.0245	0.0350	0.1562	0.024*
C3	0.14693 (13)	−0.02116 (19)	0.10985 (9)	0.0221 (3)
H3A	0.1294	−0.1404	0.0781	0.027*
H3B	0.1770	−0.0557	0.1685	0.027*
C4	0.25003 (12)	0.08583 (19)	0.06831 (9)	0.0210 (3)
H4A	0.2363	0.0749	0.0058	0.025*
H4B	0.3304	0.0257	0.0856	0.025*
C5	0.25576 (11)	0.29843 (18)	0.09305 (8)	0.0164 (3)
C6	0.12997 (11)	0.38679 (17)	0.06746 (8)	0.0159 (3)
H6A	0.1323	0.5269	0.0717	0.019*
H6B	0.0991	0.3492	0.0093	0.019*
C7	0.36254 (12)	0.39101 (19)	0.05278 (8)	0.0191 (3)
C8	−0.06329 (12)	0.40772 (18)	0.15102 (8)	0.0190 (3)
H8A	−0.1280	0.3809	0.1051	0.023*
H8B	−0.0941	0.3652	0.2054	0.023*
C9	0.26348 (11)	0.33108 (18)	0.19093 (8)	0.0166 (3)
C10	0.34971 (13)	0.2026 (2)	0.24727 (9)	0.0240 (4)
H10A	0.4190	0.1569	0.2152	0.029*	0.58 (2)
H10B	0.3039	0.0915	0.2669	0.029*	0.58 (2)
H10C	0.3135	0.0746	0.2524	0.029*	0.42 (2)
H10D	0.4314	0.1906	0.2236	0.029*	0.42 (2)
C11A	0.3987 (8)	0.3238 (7)	0.3234 (4)	0.0363 (14)	0.58 (2)
H11A	0.3857	0.2583	0.3774	0.044*	0.58 (2)
H11B	0.4881	0.3491	0.3208	0.044*	0.58 (2)
C11B	0.3616 (11)	0.3029 (7)	0.3336 (3)	0.039 (2)	0.42 (2)
H11C	0.3062	0.2437	0.3731	0.046*	0.42 (2)
H11D	0.4477	0.2952	0.3590	0.046*	0.42 (2)
C12	0.32478 (14)	0.5097 (2)	0.31658 (10)	0.0301 (4)
H12A	0.2463	0.4989	0.3444	0.036*	0.58 (2)
H12B	0.3734	0.6172	0.3418	0.036*	0.58 (2)
H12C	0.2490	0.5410	0.3450	0.036*	0.42 (2)
H12D	0.3918	0.5958	0.3385	0.036*	0.42 (2)
C13	0.30171 (13)	0.5316 (2)	0.22038 (9)	0.0233 (3)
H13A	0.3776	0.5729	0.1944	0.028*
H13B	0.2349	0.6242	0.2059	0.028*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0141 (5)	0.0224 (5)	0.0139 (5)	−0.0020 (3)	0.0023 (3)	0.0016 (3)
O2	0.0316 (6)	0.0197 (5)	0.0276 (6)	0.0021 (4)	0.0138 (4)	−0.0031 (4)
O4	0.0238 (6)	0.0341 (6)	0.0387 (7)	0.0003 (4)	0.0094 (5)	0.0193 (5)
O3	0.0179 (5)	0.0423 (7)	0.0474 (7)	0.0055 (4)	0.0126 (5)	0.0194 (5)
C1	0.0154 (6)	0.0179 (6)	0.0128 (6)	−0.0009 (4)	0.0013 (4)	0.0003 (4)
C2	0.0210 (7)	0.0185 (7)	0.0214 (7)	−0.0031 (5)	0.0037 (5)	−0.0020 (5)
C3	0.0250 (7)	0.0159 (6)	0.0261 (7)	0.0001 (5)	0.0059 (5)	−0.0006 (5)
C4	0.0225 (7)	0.0191 (7)	0.0220 (7)	0.0038 (5)	0.0069 (5)	−0.0002 (5)
C5	0.0148 (6)	0.0188 (6)	0.0160 (6)	0.0014 (4)	0.0037 (5)	0.0030 (4)
C6	0.0159 (6)	0.0175 (6)	0.0147 (6)	0.0012 (4)	0.0038 (5)	0.0022 (4)
C7	0.0174 (6)	0.0227 (7)	0.0176 (6)	0.0013 (5)	0.0046 (5)	0.0033 (5)
C8	0.0172 (6)	0.0203 (7)	0.0198 (6)	0.0002 (5)	0.0043 (5)	−0.0005 (5)
C9	0.0142 (6)	0.0198 (7)	0.0160 (6)	−0.0011 (4)	0.0037 (5)	0.0022 (4)
C10	0.0192 (7)	0.0312 (8)	0.0214 (7)	0.0042 (5)	0.0001 (5)	0.0053 (5)
C11A	0.040 (3)	0.041 (2)	0.0254 (19)	0.0053 (17)	−0.0117 (19)	0.0020 (15)
C11B	0.032 (4)	0.062 (4)	0.021 (2)	0.003 (2)	−0.005 (2)	0.002 (2)
C12	0.0248 (8)	0.0409 (9)	0.0243 (8)	−0.0052 (6)	−0.0003 (6)	−0.0076 (6)
C13	0.0216 (7)	0.0244 (7)	0.0238 (7)	−0.0058 (5)	0.0012 (5)	−0.0017 (5)

Geometric parameters (Å, º)

O1—C9	1.4558 (14)	C6—H6B	0.9900
O1—C1	1.4632 (14)	C8—H8A	0.9900
O2—C8	1.4208 (17)	C8—H8B	0.9900
O2—H2	0.8400	C9—C13	1.5355 (19)
O4—H4	0.8400	C9—C10	1.5377 (18)
O3—C7	1.257 (2)	C10—C11B	1.533 (4)
O4—C7	1.275 (2)	C10—C11A	1.537 (4)
O3—H3	0.8400	C10—H10A	0.9900
C1—C8	1.5176 (17)	C10—H10B	0.9900
C1—C6	1.5265 (17)	C10—H10C	0.9900
C1—C2	1.5287 (18)	C10—H10D	0.9900
C2—C3	1.5344 (19)	C11A—C12	1.536 (4)
C2—H2A	0.9900	C11A—H11A	0.9900
C2—H2B	0.9900	C11A—H11B	0.9900
C3—C4	1.5356 (19)	C11B—C12	1.530 (5)
C3—H3A	0.9900	C11B—H11C	0.9900
C3—H3B	0.9900	C11B—H11D	0.9900
C4—C5	1.5491 (19)	C12—C13	1.529 (2)
C4—H4A	0.9900	C12—H12A	0.9900
C4—H4B	0.9900	C12—H12B	0.9900
C5—C7	1.5102 (17)	C12—H12C	0.9900
C5—C6	1.5275 (17)	C12—H12D	0.9900
C5—C9	1.5588 (17)	C13—H13A	0.9900
C6—H6A	0.9900	C13—H13B	0.9900
C9—O1—C1	110.43 (9)	C13—C9—C5	115.46 (10)
C8—O2—H2	109.5	C10—C9—C5	118.22 (11)
C7—O4—H4	109.5	C11B—C10—C9	104.5 (3)
C7—O3—H3	109.5	C9—C10—C11A	106.60 (17)
O1—C1—C8	108.57 (10)	C11B—C10—H10A	126.0
O1—C1—C6	103.76 (10)	C9—C10—H10A	110.4
C8—C1—C6	114.64 (10)	C11A—C10—H10A	110.4
O1—C1—C2	107.52 (10)	C9—C10—H10B	110.4
C8—C1—C2	111.96 (10)	C11A—C10—H10B	110.4
C6—C1—C2	109.83 (10)	H10A—C10—H10B	108.6
C1—C2—C3	110.51 (10)	C11B—C10—H10C	110.8
C1—C2—H2A	109.5	C9—C10—H10C	110.8
C3—C2—H2A	109.5	H10A—C10—H10C	93.7
C1—C2—H2B	109.5	C11B—C10—H10D	110.8
C3—C2—H2B	109.5	C9—C10—H10D	110.8
H2A—C2—H2B	108.1	H10B—C10—H10D	122.3
C2—C3—C4	114.26 (11)	H10C—C10—H10D	108.9
C2—C3—H3A	108.7	C12—C11A—C10	105.7 (2)
C4—C3—H3A	108.7	C12—C11A—H11A	110.6
C2—C3—H3B	108.7	C10—C11A—H11A	110.6
C4—C3—H3B	108.7	C12—C11A—H11B	110.6
H3A—C3—H3B	107.6	C10—C11A—H11B	110.6
C3—C4—C5	112.61 (10)	H11A—C11A—H11B	108.7
C3—C4—H4A	109.1	C12—C11B—C10	106.2 (3)
C5—C4—H4A	109.1	C12—C11B—H11C	110.5
C3—C4—H4B	109.1	C10—C11B—H11C	110.5
C5—C4—H4B	109.1	C12—C11B—H11D	110.5
H4A—C4—H4B	107.8	C10—C11B—H11D	110.5
C7—C5—C6	114.24 (10)	H11C—C11B—H11D	108.7
C7—C5—C4	109.25 (10)	C13—C12—C11B	107.0 (2)
C6—C5—C4	108.02 (10)	C13—C12—C11A	101.6 (3)
C7—C5—C9	111.51 (10)	C13—C12—H12A	111.4
C6—C5—C9	100.61 (9)	C11B—C12—H12A	94.1
C4—C5—C9	113.03 (10)	C11A—C12—H12A	111.4
C1—C6—C5	99.95 (10)	C13—C12—H12B	111.4
C1—C6—H6A	111.8	C11B—C12—H12B	122.3
C5—C6—H6A	111.8	C11A—C12—H12B	111.4
C1—C6—H6B	111.8	H12A—C12—H12B	109.3
C5—C6—H6B	111.8	C13—C12—H12C	110.3
H6A—C6—H6B	109.5	C11B—C12—H12C	110.3
O3—C7—O4	122.98 (12)	C11A—C12—H12C	127.2
O3—C7—C5	118.7 (1)	H12B—C12—H12C	94.7
O4—C7—C5	118.4 (1)	C13—C12—H12D	110.3
O2—C8—C1	110.79 (10)	C11B—C12—H12D	110.3
O2—C8—H8A	109.5	C11A—C12—H12D	97.6
C1—C8—H8A	109.5	H12A—C12—H12D	121.7
O2—C8—H8B	109.5	H12C—C12—H12D	108.6
C1—C8—H8B	109.5	C12—C13—C9	103.23 (11)
H8A—C8—H8B	108.1	C12—C13—H13A	111.1
O1—C9—C13	107.30 (10)	C9—C13—H13A	111.1
O1—C9—C10	109.51 (10)	C12—C13—H13B	111.1
C13—C9—C10	103.15 (11)	C9—C13—H13B	111.1
O1—C9—C5	102.83 (9)	H13A—C13—H13B	109.1
C9—O1—C1—C8	−139.28 (10)	C7—C5—C9—O1	158.29 (10)
C9—O1—C1—C6	−16.93 (12)	C6—C5—C9—O1	36.77 (11)
C9—O1—C1—C2	99.40 (11)	C4—C5—C9—O1	−78.17 (12)
O1—C1—C2—C3	−52.37 (13)	C7—C5—C9—C13	41.78 (14)
C8—C1—C2—C3	−171.54 (10)	C6—C5—C9—C13	−79.74 (12)
C6—C1—C2—C3	59.91 (13)	C4—C5—C9—C13	165.33 (11)
C1—C2—C3—C4	−40.09 (15)	C7—C5—C9—C10	−81.00 (14)
C2—C3—C4—C5	39.86 (16)	C6—C5—C9—C10	157.49 (11)
C3—C4—C5—C7	177.59 (11)	C4—C5—C9—C10	42.55 (15)
C3—C4—C5—C6	−57.59 (14)	O1—C9—C10—C11A	−95.2 (4)
C3—C4—C5—C9	52.81 (15)	O1—C9—C10—C11B	−77.2 (5)
O1—C1—C6—C5	39.50 (11)	C13—C9—C10—C11A	18.8 (5)
C8—C1—C6—C5	157.73 (10)	C9—C10—C11A—C12	8.4 (7)
C2—C1—C6—C5	−75.20 (12)	C10—C11A—C12—C13	−32.3 (6)
C7—C5—C6—C1	−165.93 (11)	C11A—C12—C13—C9	44.3 (4)
C4—C5—C6—C1	72.29 (12)	C10—C9—C13—C12	−39.2 (1)
C9—C5—C6—C1	−46.36 (11)	C13—C9—C10—C11B	36.9 (5)
C6—C5—C7—O3	−174.24 (12)	C9—C10—C11B—C12	−20.1 (8)
C4—C5—C7—O3	−53.13 (17)	C10—C11B—C12—C13	−4.3 (8)
C9—C5—C7—O3	72.53 (16)	C11B—C12—C13—C9	27.0 (5)
C6—C5—C7—O4	5.56 (18)	C5—C9—C10—C11B	165.6 (5)
C4—C5—C7—O4	126.66 (13)	C5—C9—C10—C11A	147.5 (4)
C9—C5—C7—O4	−107.67 (14)	C11B—C10—C11A—C12	−77.3 (9)
O1—C1—C8—O2	72.76 (12)	C11A—C10—C11B—C12	79.0 (9)
C6—C1—C8—O2	−42.72 (14)	C10—C11B—C12—C11A	−78.8 (9)
C2—C1—C8—O2	−168.69 (10)	C10—C11A—C12—C11B	77.5 (9)
C1—O1—C9—C13	109.70 (11)	O1—C9—C13—C12	76.38 (12)
C1—O1—C9—C10	−139.01 (10)	C5—C9—C13—C12	−169.68 (11)
C1—O1—C9—C5	−12.49 (12)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1^i	0.84	1.96	2.790 (1)	170
O3—H3···O4^ii	0.84	1.83	2.636 (2)	162
O4—H4···O3^ii	0.84	1.80	2.636 (2)	171
C12—H12D···O3^iii	0.99	2.60	3.561 (2)	163

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