Regioselective Synthesis of α-erfluoroalkylated Ketals via Double Michael Addition of Alcohols to Activated Alkynes
Résumé
An efficient method was developed for the synthesis of alkyl 3,3-dialkoxy-3-(perfluoroalkyl)propanoates from ethyl 3-(perfluoroalkyl)propynoates and alcohols using a base-catalyzed double Michael addition reaction (which was accompanied by transesterification in the case of MeOH, EtOH, PrOH, and BuOH). This method provides easy access to the product α-perfluoroalkyl ketals with reasonable to good yields with total regioselectivity. This procedure does not require the use of expensive supplementary additives for the preparation of α-perfluoroalkyl ketals which are very sensitive to acidic conditions.