Cyclization studies of some vinylcycloalkanols

Abstract

Several vinylcycloalkanols have been treated with acidic reagents (most generally, formic acid) in order to study the synthetic, mechanistic, and stereochemical potentials of their cyclizations. The model systems initially chosen for study were 2-(3-butenyl)-1-vinylcyclopentanol (7) and 2-(3-butenyl)-1-vinylcyclohexanol (8). The former alcohol was found to yield both a hydrindane and a hydroazulene ring system upon treatment with formic acid (equation 1). Reaction conditions could not be found which would give either product to the exclusion of the other. Cyclohexanol 0 gave only a decalin system upon treatment with anhydrous formic acid (equation 2). Conducting both cyclizations with deuterioformic acid and ([structure 7], [structure 8]) analyzing the products for deuterium incorporation gave information about the reaction mechanisms.