Dimethyl 7-methoxytetracyclo[6.4.0.02,4.03,7]dodeca-1(12),5,8,10-tetraene-3,4-dicarboxylate

The title compound, C17H16O5, is a previously unreported substituted semibulvalene cage compound (that is, a tricyclic hydrocarbon formed from one cyclopropane and two cyclopentene rings which also has one double bond fused to a benzene ring). It has one methoxy substituent attached to the bridgehead C atom that links only the two cyclopentene rings and two methyl carboxylate groups located on the C atom shared by all three non-benzene rings and that shared only between the cyclopropane and the cyclopentene rings. The stereochemistry of the two enantiomers (racemate) that assemble in each unit cell is RRRS and SSSR. In the crystal, molecules are linked via C—H...O hydrogen bonds and C—H...π interactions, forming double-layered sheets lying perpendicular to the a axis