14-Methoxy-2,16-dioxapentacyclo[7.7.5.01,21.03,8.010,15]henicosa-3(8),10,12,14-tetraene-7,20-dione

Weicheng Lu; Chaomei Lian; Yan Yang; Yulin Zhu

doi:10.1107/S1600536811028972

. 2011 Jul 23;67(Pt 8):o2108. doi: 10.1107/S1600536811028972

14-Methoxy-2,16-dioxapentacyclo[7.7.5.0^1,21.0^3,8.0^10,15]henicosa-3(8),10,12,14-tetraene-7,20-dione

Weicheng Lu ^a, Chaomei Lian ^a, Yan Yang ^a, Yulin Zhu ^a,^*

PMCID: PMC3213550 PMID: 22091127

Abstract

The title compound, C₂₀H₂₀O₅, was synthesized from the reaction between 3-methoxysalicaldehyde and 1,3–cyclohexanedione in the presence of palladium(II) chloride. The two fused xanthene rings and one of the six-membered cyclohexane rings adopt envelope conformations, while the other six-membered cyclohexane ring is in a chair conformation. The molecular packing is stabilized by weak intermolecular C—H⋯O interactions.

Related literature

For applications of xanthene derivatives, see: Banerjee & Mukherjee (1981 ▶); Lambert et al. (1997 ▶); Hideo (1981 ▶); Poupelin et al. (1978 ▶); Menchen et al. (2003 ▶); Ravindranath & Seshadri (1973 ▶); Bigdeli et al. (2007 ▶). For the construction of xanthene derivatives, see: Fan et al. (2005 ▶); Jin et al. (2004 ▶, 2005 ▶); Srihari et al. (2008 ▶); Wang & Harvey (2002 ▶).

Experimental

Crystal data

C₂₀H₂₀O₅
M _r = 340.36
Monoclinic,
a = 11.0939 (15) Å
b = 12.5918 (17) Å
c = 12.2982 (16) Å
β = 104.846 (2)°
V = 1660.6 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 298 K
0.32 × 0.28 × 0.25 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.970, T _max = 0.976
10066 measured reflections
3882 independent reflections
2361 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.057
wR(F ²) = 0.162
S = 1.06
3882 reflections
231 parameters
13 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.17 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811028972/rk2283sup1.cif

e-67-o2108-sup1.cif^{(21.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811028972/rk2283Isup2.hkl

e-67-o2108-Isup2.hkl^{(190.3KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811028972/rk2283Isup3.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
C11—H11B⋯O5ⁱ	0.97	2.57	3.538 (4)	175
C10—H10B⋯O3ⁱⁱ	0.97	2.59	3.466 (4)	151
C10—H10A⋯O1ⁱⁱⁱ	0.97	2.40	3.367 (3)	175
C3—H3A⋯O3ⁱⁱ	0.97	2.52	3.389 (3)	149

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

Acknowledgments

The authors thank South China Normal University for financial support (grant SCNUG21096).

supplementary crystallographic information

Comment

Xanthenes and benzoxanthenes are important biologically active heterocyclic compounds, which possess antiviral, anti–inflammatory and antibacterial activities (Banerjee & Mukherjee 1981; Lambert et al., 1997; Hideo 1981; Poupelin et al., 1978; Menchen et al., 2003; Ravindranath & Seshadri 1973). They are also implicated in photodynamic therapy, examples including myrtucommulone–E, chromenes, rhodomyrtone (Bigdeli et al., 2007). Various literature procedures are available to synthesis xanthenes (Fan et al., 2005; Jin et al., 2004, 2005; Srihari et al., 2008; Wang & Harvey 2002). In the presence of palladium(II) chloride, the reaction between 3–methoxysalicyladehyde and 1,3–cyclohexanedione proceeded to give the title compound (Fig. 1). The molecular structure of the title compound is illustrated in Fig. 2. There are no unusual bond lengths and angles in the compound. The title molecule is built up from five fused rings via phenyl, xanthene, and cyclohexane. The two fused xanthene rings adopt envelope conformations, one of the six–membered cyclohexane rings is also in an envelope conformation and the other is in chair conformations. In addition, the molecules in the structure are linked via paired C18—H2A, O3—H10B, O1—H20B et al. short–contaction force.

Experimental

A mixture of 3–methoxysalicyladehyde (0.76 g, 5 mmol), 1,3–cyclohexanedione (1.12 g, 10 mmol), and palladium(II) chloride (0.002 g) was refluxed in acetonitrile (12 ml) at 353 K for 12 h. After being cooled to room temperature, the reaction mixture was poured into water. The white precipitate was filtered off with a silica pad, washed twice with cool water, and the filtrate was then dried under vacuum to yield the product in yield of 90%. Single crystals of the title compound were obtained by slow evaporation from ethanol at room temperature to yield colourless, block–shaped crystal.