Bicycloannulation with isopropenyltriphenylphosphonium bromide. The synthesis of trachyloban-19-oic acid
Abstract
1-Methyltricyclo[3.2.1.02,7]octan-6-ones can be prepared in one step from the α′-enolates of αβ-cyclohexenones and isopropenyltriphenylphosphonium bromide; this reaction has been employed as the key step in a synthesis of trachyloban-19-oic acid from podocarpic acid.