K. Chinnakali et al., 4-METHYL-7,10-DIHYDROBENZO[H]COUMARIN AND THYL-7,8,9,10-TETRAHYDRO-8,9-EPOXYBENZO[H]COUMARIN, Acta crystallographica. Section C, Crystal structure communications, 54, 1998, pp. 542-544
The coumarin rings in the title molecules, C14H12O2 and C14H12O3, are
planar. in the epoxide derivative, the tetrahydrobenzene ring adopts a
boat conformation and the oxirane plane is nearly perpendicular to th
e coumarin moiety.