Synthesis of tercyclohexanones

Article abstract of DOI:10.1055/s-1990-27091

A synthetic route to tercyclohexanones is described in which alkylation of 4-cyclohexylcyclohexanone with the dianion of 4,4-(ethylenedioxy)cyclohexanecarboxylic acid gives 1-carboxy-1'-hydroxyl-1,1':4',1''-tercyclohexan-4-one ethylene ketal. Decarboxylative dehydration of the latter followed by hydrolysis of the ketal gives 4-(4'-cyclohexylcyclohexylidene)cyclohexanone. Hydrogenation of this compound gives cis- and trans-1,1':4',1''-tecyclohexan-4-one, the latter of which is correlated with authentic trans-1,1':4',1''-tercyclohexane.