1-(5,7-Dihy­droxy-2,2-dimethylchroman-6-yl)ethanone

Matthew P Akerman; Zimbili Mkhize; Fanie R van Heerden

doi:10.1107/S1600536811047982

. 2011 Nov 23;67(Pt 12):o3412. doi: 10.1107/S1600536811047982

1-(5,7-Dihydroxy-2,2-dimethylchroman-6-yl)ethanone

Matthew P Akerman ^a,^*, Zimbili Mkhize ^a, Fanie R van Heerden ^a

PMCID: PMC3239049 PMID: 22199897

Abstract

In the title molecule, C₁₃H₁₆O₄, the pyran ring is in a half-chair conformation. There is an intramolecular hydrogen bond involving the ketone O atom and an H atom of a phenol group which forms an S(6) ring. The ketone O atom is also involved in an intermolecular hydrogen bond with a different phenolic H atom of a symmetry-related molecule, forming C(6) chains along the c-axis direction.

Related literature

For applications of the title compound, see: Kraus et al. (2011 ▶); Basabe et al. (2010 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For a related structure, see: Chakkaravarthi et al. (2007 ▶).

Experimental

Crystal data

C₁₃H₁₆O₄
M _r = 236.26
Tetragonal,
a = 10.5677 (2) Å
c = 21.4244 (5) Å
V = 2392.6 (1) Å³
Z = 8
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 298 K
0.6 × 0.4 × 0.4 mm

Data collection

Oxford Diffraction Xcalibur 2 CCD diffractometer
Absorption correction: multi-scan (SORTAV; Blessing, 1995 ▶) T _min = 0.955, T _max = 0.962
26011 measured reflections
2366 independent reflections
2046 reflections with I > 2σ(I)
R _int = 0.047

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.091
S = 1.08
2366 reflections
166 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.12 e Å⁻³
Δρ_min = −0.11 e Å⁻³
Absolute structure: Flack (1983 ▶), 931 Friedel pairs
Flack parameter: 0.7 (11)

Data collection: CrysAlis CCD (Oxford Diffraction, 2008 ▶); cell refinement: CrysAlis CCD; data reduction: CrysAlis RED (Oxford Diffraction, 2008 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: WinGX (Farrugia, 1999 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S1600536811047982/lh5372sup1.cif

e-67-o3412-sup1.cif^{(22KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811047982/lh5372Isup2.hkl

e-67-o3412-Isup2.hkl^{(114KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811047982/lh5372Isup3.mol

Supplementary material file. DOI: 10.1107/S1600536811047982/lh5372Isup4.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H102⋯O4ⁱ	0.97 (2)	1.77 (2)	2.737 (2)	179 (1)
O3—H103⋯O4	0.86 (2)	1.71 (2)	2.501 (2)	151 (2)

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Symmetry code: (i) Inline graphic .

Acknowledgments

We would like to thank the University of KwaZulu-Natal for their facilities and Kirsty Stewart for the data collection. We also wish to acknowledge the National Research Foundation of South Africa for their financial support.

supplementary crystallographic information

Comment

The title compound was synthesized as an intermediate in the preparation of flavonoids or other phenolic derivatives and an intermediate for an anti-HIV chromanone (Kraus et al., 2011). It has also been obtained as a side product in the preparation of prenylated flavonoids with antitumour activity (Basabe et al., 2010). The molecular structure of the title compound is shown in Fig. 1. The pyran ring is in a half-chair conformation. There are two types of hydrogen bonds, one intramolecular and one intermolecular. The intramolecular O3—H103···O4 hydrogen bond forms an S(6) ring motif (Bernstein et al., 1995). This hydrogen bond motif is common to molecules which contain derivatized (2-hydroxyphenyl)ethanone structures (Chakkaravarthi et al., 2007). In addition to the intramolecular hydrogen bonding, there is an intermolecular hydrogen bond between the phenolic group and the ketone O atom of an adjacent molecule. This O2—H102···O4ⁱ (see Table 1 for symmetry code) hydrogen bond links the molecules to form infinite one-dimensional C(6) chains parallel to the c axis (base vector [0 0 1]). The same ketone oxygen atom therefore accepts two hydrogen bonds, one intermolecular and one intramolecular. The hydrogen bond lengths and bond angles are summarized in Table 1. Fig.2 depicts both the intermolecular and intramolecular hydrogen bonds. The length of intermolecular hydrogen bond is 0.303 Å shorter than the sum of the van der Waals radii. Although the length of hydrogen bonds does not necessarily correlate linearly with bond strength, due to packing constraints in the lattice, it is probable that this very short bond is moderate to strong. This is especially likely considering that the bond angle very closely approaches ideality.

Experimental

To a solution of 6-hydroxy-2,4-dimethoxymethyloxy-3-prenylacetophenone (80 mg, 0.25 mmol) in methanol (20 ml) was added 1.0 M HCl (6 ml). The reaction mixture was refluxed for 1 h before cooling. The solvent was evaporated and the residue purified by column chromatography using hexane:ethyl acetate: 2:1 to afford 1-(5,7-dihydroxy-2,2-dimethylchroman-6-yl)ethanone as yellow crystals (10 mg, 17%): mp 501–502 K;