(2,3-Dihydro-1,4-benzodioxin-2-yl)methanol

In the title compound, C₉H₁₀O₃, the heterocyclic ring has a half-chair conformation. The –CH₂OH substituent is attached equatorially with respect to the heterocyclic ring. In the crystal structure, the mol­ecules are linked by O—H...O hydrogen bonds, with the hydroxyl O atom functioning both as donor and acceptor. This results in the formation of C(2) helical chains running along the fourfold screw axes.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C)= 0.002 Å
• R factor = 0.041
• wR factor = 0.108
• Data-to-parameter ratio = 16.8

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S1. Comment

The 2,3-dihydro-1,4-benzodioxin ring system is present in a large number of structures of therapeutic agents possessing important biological activities (Guillaumet, 1996). As part of our ongoing investigation of this kind of system, we recently prepared the title compound, (I), and present here its crystal structure.

The structure of (I) is shown in Fig. 1. The six-membered ring containing O atoms adopts a half-chair conformation. The Cremer & Pople (1975) puckering parameters for this ring are Q = 0.5095 (11), θ = 51.72 (13)° and φ = 151.75 (14)°. The methanol group attached to C7 is in an equatorial position.

In the crystal structure, molecules form helical chains along c, involving their hydroxyl groups both as donors and acceptors of hydrogen bonds (Table 2), with graph set C(2) (Bernstein et al., 1995), via crystallographic fourfold screw axes (Fig. 2).

Related literature

Crystal structures of the salts of the closely related (S)- and (R)-1,4-benzodioxane-2-carboxylic acids with (S)-1-phenylethylamine and its p-methyl- and p-nitro-substituted analogues have been determined. All of them consist of chains running along a twofold screw axis built up by hydrogen-bond interactions, involving the ammonium group NH₃⁺ and the carboxylic O atoms (Marchini et al., 2005).

For related literature, see: Bernstein et al. (1995); Bolchi et al. (2003); Cremer & Pople (1975); Guillaumet (1996).

S2. Experimental

The title compound was obtained as follows. Catechol (1.0 equivalent) was added at room temperature to a solution of K₂CO₃ (2.5 equivalents) in distilled water and the resulting solution was stirred for 30 min. Epichlorohydrin (1.3 equivalents) was then added dropwise and warmed at 343 K for 6 h. After cooling to room temperature, the reaction mixture was diluted and extracted (CH₂Cl₂), the organic layer dried (Na₂SO₄), filtered and concentrated, and the crude product purified by flash chromatography (gradient elution EtOAc–hexane 1:5 → 1:1.5). The title compound was obtained (46% yield) as a white solid [m.p. 360–361 K (literature value 362.35 K; Bolchi et al., 2003)]. Suitable crystals of (I) were obtained after dissolving the compound in the minimum volume of CH₂Cl₂. A vial with a screw top allowed the slow evaporation of the solvent at room temperature to produce colourless crystals.

S3. Refinement

The hydroxy H atom was located in a difference map and refined as riding, with O—H = 0.84 Å and with U_iso(H) = 1.2U_eq(O). Other H atoms were positioned geometrically and treated as riding, with C—H = 0.95–0.99 Å and with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: publCIF (Westrip, 2007).

Figures

	Fig. 1. The molecular structure of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are represented as spheres of arbitrary radii.
	Fig. 2. A view, down the c axis, of the molecular packing of (I). The intermolecular hydrogen bonds are shown as dashed lines.

(2,3-Dihydro-1,4-benzodioxin-2-yl)methanol

Crystal data

C9H10O3	Dx = 1.374 Mg m^−3
Mr = 166.17	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, I41/a	Cell parameters from 4441 reflections
Hall symbol: -I 4ad	θ = 1.8–28.3°
a = 22.5161 (10) Å	µ = 0.10 mm^−1
c = 6.3400 (6) Å	T = 100 K
V = 3214.2 (4) Å^3	Prism, colourless
Z = 16	0.55 × 0.23 × 0.15 mm
F(000) = 1408

Data collection

Bruker SMART APEX CCD area-detector diffractometer	1883 independent reflections
Radiation source: fine-focus sealed tube	1716 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.024
φ and ω scans	θmax = 28.3°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −25→29
Tmin = 0.955, Tmax = 0.985	k = −18→29
9739 measured reflections	l = −8→7

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) = 0.108	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0545P)^2 + 3.1875P] where P = (Fo^2 + 2Fc^2)/3
1883 reflections	(Δ/σ)max = 0.001
112 parameters	Δρmax = 0.35 e Å^−3
1 restraint	Δρmin = −0.21 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	0.79405 (5)	0.30835 (5)	0.4847 (2)	0.0185 (3)
C2	0.82759 (6)	0.27676 (6)	0.6307 (2)	0.0235 (3)
H2	0.8132	0.2715	0.7703	0.028*
C3	0.88200 (6)	0.25297 (6)	0.5731 (2)	0.0258 (3)
H3A	0.9047	0.2312	0.6728	0.031*
C4	0.90330 (6)	0.26102 (6)	0.3693 (2)	0.0258 (3)
H4	0.9410	0.2454	0.3308	0.031*
C5	0.86967 (6)	0.29177 (6)	0.2219 (2)	0.0226 (3)
H5	0.8844	0.2971	0.0827	0.027*
C6	0.81441 (5)	0.31479 (5)	0.2776 (2)	0.0177 (3)
O1	0.78152 (4)	0.34302 (4)	0.12524 (14)	0.0197 (2)
C7	0.71960 (5)	0.34921 (5)	0.1827 (2)	0.0194 (3)
H7	0.7008	0.3090	0.1812	0.023*
C8	0.71610 (6)	0.37380 (6)	0.4038 (2)	0.0233 (3)
H8A	0.7386	0.4115	0.4125	0.028*
H8B	0.6742	0.3821	0.4408	0.028*
O2	0.74068 (4)	0.33105 (4)	0.54951 (14)	0.0236 (2)
C9	0.68964 (6)	0.38742 (6)	0.0181 (2)	0.0214 (3)
H9A	0.6953	0.3689	−0.1221	0.026*
H9B	0.6465	0.3885	0.0473	0.026*
O3	0.71146 (4)	0.44630 (4)	0.01122 (16)	0.0256 (2)
H3	0.7420 (7)	0.4480 (8)	−0.065 (3)	0.031*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0192 (6)	0.0155 (5)	0.0208 (6)	−0.0012 (4)	−0.0018 (5)	−0.0021 (4)
C2	0.0280 (7)	0.0212 (6)	0.0213 (6)	−0.0025 (5)	−0.0053 (5)	−0.0003 (5)
C3	0.0253 (6)	0.0196 (6)	0.0325 (7)	0.0001 (5)	−0.0132 (5)	−0.0012 (5)
C4	0.0162 (6)	0.0227 (6)	0.0385 (8)	0.0011 (5)	−0.0045 (5)	−0.0059 (5)
C5	0.0186 (6)	0.0224 (6)	0.0268 (7)	−0.0018 (5)	0.0008 (5)	−0.0026 (5)
C6	0.0178 (6)	0.0145 (5)	0.0209 (6)	−0.0021 (4)	−0.0019 (4)	−0.0011 (4)
O1	0.0177 (4)	0.0227 (4)	0.0186 (4)	0.0020 (3)	0.0017 (3)	0.0023 (3)
C7	0.0169 (6)	0.0201 (6)	0.0211 (6)	0.0007 (4)	0.0018 (5)	0.0000 (5)
C8	0.0245 (6)	0.0255 (6)	0.0198 (6)	0.0068 (5)	0.0011 (5)	0.0004 (5)
O2	0.0244 (5)	0.0286 (5)	0.0177 (5)	0.0070 (4)	0.0026 (4)	0.0025 (4)
C9	0.0215 (6)	0.0229 (6)	0.0198 (6)	0.0018 (5)	−0.0003 (5)	0.0008 (5)
O3	0.0272 (5)	0.0195 (5)	0.0299 (5)	0.0040 (4)	0.0082 (4)	0.0016 (4)

Geometric parameters (Å, º)

C1—O2	1.3689 (15)	O1—C7	1.4477 (14)
C1—C2	1.3906 (17)	C7—C8	1.5091 (18)
C1—C6	1.3981 (18)	C7—C9	1.5118 (17)
C2—C3	1.3861 (19)	C7—H7	1.0000
C2—H2	0.9500	C8—O2	1.4443 (15)
C3—C4	1.390 (2)	C8—H8A	0.9900
C3—H3A	0.9500	C8—H8B	0.9900
C4—C5	1.3878 (19)	C9—O3	1.4146 (15)
C4—H4	0.9500	C9—H9A	0.9900
C5—C6	1.3934 (17)	C9—H9B	0.9900
C5—H5	0.9500	O3—H3	0.840 (14)
C6—O1	1.3732 (15)
O2—C1—C2	117.89 (11)	O1—C7—C9	108.11 (10)
O2—C1—C6	122.08 (11)	C8—C7—C9	114.17 (10)
C2—C1—C6	120.01 (11)	O1—C7—H7	108.6
C3—C2—C1	120.15 (13)	C8—C7—H7	108.6
C3—C2—H2	119.9	C9—C7—H7	108.6
C1—C2—H2	119.9	O2—C8—C7	109.24 (10)
C2—C3—C4	119.97 (12)	O2—C8—H8A	109.8
C2—C3—H3A	120.0	C7—C8—H8A	109.8
C4—C3—H3A	120.0	O2—C8—H8B	109.8
C5—C4—C3	120.18 (12)	C7—C8—H8B	109.8
C5—C4—H4	119.9	H8A—C8—H8B	108.3
C3—C4—H4	119.9	C1—O2—C8	113.15 (10)
C4—C5—C6	120.14 (13)	O3—C9—C7	113.55 (11)
C4—C5—H5	119.9	O3—C9—H9A	108.8
C6—C5—H5	119.9	C7—C9—H9A	108.9
O1—C6—C5	118.39 (11)	O3—C9—H9B	108.9
O1—C6—C1	122.12 (11)	C7—C9—H9B	108.9
C5—C6—C1	119.49 (11)	H9A—C9—H9B	107.7
C6—O1—C7	112.76 (9)	C9—O3—H3	110.1 (12)
O1—C7—C8	108.63 (10)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O3^i	0.84 (1)	1.80 (1)	2.6348 (11)	172 (2)

Symmetry code: (i) −y+5/4, x−1/4, z−1/4.