Synthesis of 6-substituted 5,6,7,12-tetrahydrodibenzo[a,d]cyclooctenes

Abstract

The eight-membered ring 6,6-dicyano-5,6,7,12-tetrahydrodibenzo[a,d]cyc1ooctene was prepared from 2,2'-bis(brornomethy1)diphenylmethane and sodiomalononitrile. From this dicyano derivative a series of mono-and disubstituted cyclooctenes was synthesized.The corresponding 5,7,12-trihydro-6H-dibenzo[a,d]cycloocten-one was obtained by the ring enlargement of 5,10-dihydro-llH-dibenzo[a,d]cyclohepten-11-one with diazomethane. The parent compound and its dideuterio derivative were prepared from the eight-membered ring ketone. A Wittig reaction on the ketone gave the methylene derivative.