9-Ethoxy-1,5,13-trimethyl-8,10-dioxatetracyclo[7.7.1.02,7.011,16]heptadeca-2,4,6,11,13,15-hexaene

The reaction of ethyl acetoacetate with meta-cresol in an acidic ionic liquid yielded a complex mixture of condensation products. 4,7-Dimethylcoumarin and the title compound, C20H22O3, were isolated. The title compound shows chemical but not crystallographic mirror symmetry. The two aromatic rings are inclined at an angle of 73.55 (6)°.