Synthesis of optically active 10,11-dihydro-5h-dibenzo[a,d]cycloheptenes

Abstract The dicarboxylic acid 8 was synthesized from dibenzosuberone by dehydrogenation, reduction of the keto group and dicarboxylation. After resolution with cinchonine the (-)-enantiomer served as starting material for various transformation products with trans-configuration of the substituents at the 10,11-positions. Ring closure between these two groups led to the introduction of an additional homo- or heterocyclic ring. Attempted bromination of the dimethyl ester 9 of 8 gave the lactone 49 instead, LAH reduction of which resulted in formation of the corresponding ether bridge. Of both bridged compounds several derivatives have been prepared by modification of the substituent at C(11). Furthermore the products of nitration of the 5-keto derivatives 31 and 36 are described as well as some thio analogues and products containing one additional heteroring.