4a-Hy­droxy-9-(2-meth­oxy­phen­yl)-4,4a,5,6,7,8,9,9a-octa­hydro-3H-xanthene-1,8(2H)-dione

Wan-Sin Loh; Hoong-Kun Fun; B Palakshi Reddy; V Vijayakumar; S Sarveswari

doi:10.1107/S1600536810050191

. 2010 Dec 4;67(Pt 1):o35–o36. doi: 10.1107/S1600536810050191

4a-Hydroxy-9-(2-methoxyphenyl)-4,4a,5,6,7,8,9,9a-octahydro-3H-xanthene-1,8(2H)-dione

Wan-Sin Loh ^a,^‡, Hoong-Kun Fun ^a,^*,^§, B Palakshi Reddy ^b, V Vijayakumar ^b, S Sarveswari ^b

PMCID: PMC3050262 PMID: 21522746

Abstract

In the title compound, C₂₀H₂₂O₅, an S(6) ring motif is formed by an intramolecular C—H⋯O hydrogen bond, which contributes to the stabilization of the molecule. In the xanthene system, the cyclohexane ring adopts a chair conformation, the cyclohexene ring adopts a half-boat conformation and the tetrahydropyran ring adopts a half-chair conformation. The mean plane of the four essentially planar atoms of the tetrahydropyran ring [r.m.s deviation = 0.092 (1) Å] forms a dihedral angle of 64.13 (6)° with the mean plane of the methoxyphenyl group. In the crystal, intermolecular O—H⋯O and weak C—H⋯O hydrogen bonds link molecules into chains along the a axis, which are further stabilized by C—H⋯π interactions.

Related literature

For background to and the biological activity of xanthenes and their derivatives, see: Menchen et al. (2003 ▶); Saint-Ruf et al. (1972 ▶); Ion et al. (1998 ▶); Knight & Stephens (1989 ▶); Jonathan et al. (1988 ▶). For ring conformations, see: Cremer & Pople (1975 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For standard bond-length data, see: Allen et al. (1987 ▶). For a related structure, see: Reddy et al. (2009 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₂₀H₂₂O₅
M _r = 342.38
Triclinic,
a = 7.1060 (1) Å
b = 7.8897 (1) Å
c = 15.1001 (2) Å
α = 91.285 (1)°
β = 101.251 (1)°
γ = 101.129 (1)°
V = 813.10 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 100 K
0.44 × 0.23 × 0.10 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009) ▶ T _min = 0.957, T _max = 0.990
21213 measured reflections
4715 independent reflections
4132 reflections with I > 2σ(I)
R _int = 0.025

Refinement

R[F ² > 2σ(F ²)] = 0.038
wR(F ²) = 0.110
S = 1.05
4715 reflections
231 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.46 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008) ▶; program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810050191/lh5179sup1.cif

e-67-00o35-sup1.cif^{(22.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810050191/lh5179Isup2.hkl

e-67-00o35-Isup2.hkl^{(230.9KB, hkl)}

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

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

Cg1 is the centroid of the C14–C19 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O5—H1O5⋯O3ⁱ	0.87 (2)	1.93 (2)	2.7877 (11)	166.3 (18)
C6—H6A⋯O4	0.98	2.32	2.9266 (12)	120
C16—H16A⋯O5ⁱⁱ	0.93	2.53	3.4172 (13)	160
C20—H20B⋯Cg1ⁱⁱ	0.96	2.67	3.5206 (13)	147

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

HKF and WSL thank Universiti Sains Malaysia (USM) for the Research University Grant (1001/PFIZIK/811160). WSL also thanks the Malaysian Government and USM for the award of a Research Fellowship. VV is grateful to the DST–India for funding through the Young Scientist Scheme (Fast Track Proposal).

supplementary crystallographic information

Comment

Xanthene derivatives are very important heterocyclic compounds and due to their useful spectroscopic properties, they have been widely used as dyes, fluorescent materials for visualization of bio-molecules and in laser technologies (Menchen et al., 2003; Saint-Ruf et al., 1972; Ion et al., 1998). They have been reported for their agricultural bactericide activity, photodynamic therapy, antiflammatory effect and antiviral activity (Knight & Stephens, 1989; Jonathan et al., 1988). Due to their wide range of applications, these compounds have received a great deal of attention in connection with their synthesis. In the synthesis of these compounds, intermediates play a key role, because these compounds can be easily converted into acridines and other biological active compounds.

In the title compound, an intramolecular C6—H6A···O4 hydrogen bond (Table 1) contributes to the stabilization of the molecule (Fig. 1), forming an S(6) ring motif (Bernstein et al., 1995). The xanthene ring system consists of three rings which adopt different conformations. The cyclohexane ring (C1–C6) adopts a chair conformation with the puckering parameters Q = 0.5427 (11) Å, Θ = 4.67 (12)°, φ = 169.6 (15)° (Cremer & Pople, 1975). The cyclohexene ring (C8–C13) and the tetrahydropyran ring (O1/C1/C6/C7/C8/C13) adopt half-boat and half-chair conformations, with the puckering parameters, Q = 0.4831 (11) Å, Θ = 61.06 (13)°, φ = 176.13 (15)° and Q = 0.4497 (10) Å, Θ = 47.24 (13)°, φ = 87.44 (17)° (Cremer & Pople, 1975), respectively. The mean plane of the essentially planar atoms of the tetrahydropyran ring (C7/C8/C13/O1) [r.m.s deviation = 0.092 (1) Å] forms a dihedral angle of 64.13 (6)° with the methoxyphenyl group (C14–C20/O4). The bond lengths (Allen et al., 1987) and angles are within the normal range and are comparable to the related structure (Reddy et al., 2009).

In the crystal packing (Fig. 2), intermolecular O5—H1O5···O3ⁱ and C16—H16A···O5ⁱⁱ hydrogen bonds (see Table 1 for symmetry codes) link molecules into chains along the a axis which are further stabilized by C—H···Cg1ⁱⁱ interactions (Table 1), involving C14–C19 ring.

Experimental

A mixture of 2-methoxybenzaldehyde (0.365 ml, 0.0025 mol) and 1,3-cyclohexanedione (0.56 g, 0.005 mol) was refluxed in acetonitrile for 3 h. The progress of the reaction was monitored by TLC. After completion of the reaction, it was kept for 2 days for solid formation. The pure product was obtained by recrystallization of the crude product from ethanol. M.p.: 493–495 K, yield: 72%.