A novel enantiospecific route to 10-hydroxyfenchone: a convenient intermediate for C(10)-O-substituted fenchones

A novel, highly efficient enantiospecific preparation of 10-hydroxyfenchone from commercially available fenchone is described. The three-step synthetic route is based on two consecutive Wagner–Meerwein rearrangements of the fenchone skeleton, taking place with a high overall yield. This straightforward access to optically active 10-hydroxyfenchone, together with the scope for further functionalisation of the hydroxyl group, makes 10-hydroxyfenchone a convenient key intermediate to other optically active C(10)-O-substituted fenchones, which are analogues of well-known C(10)-O-substituted camphor-derived chiral sources.