Regioselective Rearrangement of 4,4-Disubstituted 2-Hydroxycyclohexa-2,5-Dienones under Deoxyfluorination Conditions.

The dienone-phenol rearrangement is a useful tool for the synthesis of highly substituted phenols. In our previous study of the rearrangement of 4,4-disubstituted 2-hydroxycyclohexa-2,5-dienone under deoxyfluorination conditions, bond migration proceeded with very poor regioselectivity. In this paper, an acid-mediated rearrangement of O-perfluoroalkylsulfonyl difluorides with regioselective migration toward the β'-carbon is reported. This method allowed the synthesis of a fluorinated analog of allocolchicinoids with improved total yield. Successful application to other substrates was also demonstrated.