Studies on alkylation of bicyclo[2.2.2]octenones and 3,3-sigmatropic shift: synthesis of advanced cis-decalins

A stereoselective method for alkylation of bicyclo[2.2.2]octenones and their 3,3-sigmatropic shift leading to cis-decalins containing various types of appendages is described. A simple and convenient method for the introduction of a butenyl chain onto the bicyclooctenones employing 1,4-dibromobutane as an equivalent of 4-bromobutene, was developed.