Wang Guang-Cheng, Yang Ying-Hong
Acta Crystallogr Sect E Struct Rep Online. 2011 May 1;67(Pt 5):o1265. doi: 10.1107/S1600536811015236. Epub 2011 Apr 29.
The title compound, C(23)H(24)O(6), crystallizes with two independent mol-ecules (A and B) in the asymmetric unit. The dihedral angles between the benzopyran ring and the α,β-unsaturated ketone unit and between the α,β-unsaturated ketone group and the benzene ring are 9.4 (10) and 12.96 (13)°, respectively, in mol-ecule A and 1.40 (17) and 4.44 (17)°, respectively, in mol-ecule B. The two meth-oxy groups at the meta positions of the benzene ring are close to being coplanar with the ring [C-O-C-C = 6.2 (3) and -1.4 (3)° in mol-ecule A and -4.2 (4) and 3.7 (3)° in mol-ecule B], whereas the third meth-oxy group, at the para position, is (+)-anti-clinal with respect to the benzene ring [C-O-C-C = 81.7 (3)°] in mol-ecule A and is (-)-synclinal with respect to the benzene ring [C-O-C-C = -103.2 (3)°] in mol-ecule B. In both independent mol-ecules, the hy-droxy group is involved in an intra-molecular O-H⋯O hydrogen bond.
