9-(2-Hydroxy-4,4-dimethyl-6-oxocyclohex-1-en-1-yl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-xanthen-1-one

Abstract

The cyclo­hexene ring that constitutes a part of the tetra­hydroxanthene fused-ring system of the title compound, C23H26O4, adopts a flattened half-chair conformation that approximates an envelope conformation (in which the methyl­ene C atom bearing the two methyl substituents represents the flap) as five of the six atoms lie approximately on a plane (r.m.s. deviation = 0.020 Å). The mean plane of the cyclo­hexene ring with the hy­droxy substituent is approximately perpendicular to the mean plane of the tetra­hydroxanthene system. In the crystal, adjacent mol­ecules are linked by O—H⋯Ocarbon­yl hydrogen bonds into a chain running along the b axis.

9-(2-Hydroxy-6-oxocyclohex-1-en-1-yl)-2,3,4,9-tetrahydro-1H-xanthen-1-one

“…The cyclohexene ring (C1-C6) attached to the xanthene system adopts an envelope conformation with the puckering parameters of Q T = 0.477 (3) Å, θ = 60.5 (2) ° and φ = 178.1 (3) °. The bond lengths and bond angles fall within a normal range and are comparable with those of the similar structures previously reported (Mohamed et al, 2012b;Kurbanova et al, 2012;Abdelhamid et al, 2011;Mohamed et al, 2011;Reddy et al, 2009).…”

“…For the bioactivity of xanthene compounds, see: Mohamed et al (2012a); Mo et al (2010) and for their fluorescence properties, see: Menchen et al (2003). For similar structures see: Mohamed et al (2011Mohamed et al ( , 2012b; Kurbanova et al (2012); Abdelhamid et al (2011); Reddy et al (2009). For ring conformations, see: Cremer & Pople (1975).…”