A versatile method for the preparation of perhydroazulenes and cis-fused 1 -decalones is described and exemplified by the synthesis of the title compounds. ... In a recent communication1 we have described the preparation of epoxy-bridged perhydroazulenes, of the type (1), by the intramolecular cycloaddition of isolated olefinic bonds to 3- oxidopyrylium species, themselves generated under mild conditions from the corresponding pyranulose acetates.a In order to use ...