title: Ethyl (2S,4R)-4-(4-bromo-phen-yl)-2-hydr-oxy-5,10-dioxo-3,4,5,10-tetra-hydro-2H-benzo[g]chromene-2-carboxyl-ate.
abstract: In the crystal structure of the title compound, C(22)H(17)BrO(6), the quinone ring makes a dihedral angle of 81.84 (3)° with the benzene ring. The chiral C atoms, viz. the ring C atoms bearing the hydr-oxy and bromo-phenyl substituents, exhibit R and S configurations, respectively. The terminal ethyl group of the -CO(2)CH(2)CH(3) group is disordered over two sets of sites with site-occupancy factors of 0.64 (1) and 0.36 (1). Inter-molecular O-H⋯O inter-actions further stabilize the crystal packing.
authors.affiliation: State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Wang
authors.forename: Guangcun
authors.initials: G
authors.lastname: Zhang
authors.forename: Xiangsheng
authors.initials: X
authors.lastname: Xu