Facile Synthesis of <i>cis</i>-2-Alkyl-3-trialkylsilyloxycycloalkanones via the Non-Aldol Aldol Rearrangement of 2,3-Epoxycycloalkanols

Abstract

Silyl triflate-promoted rearrangement of cis-2,3-epoxycycloalkanols A, prepared by epoxidation of the cyclic allylic alcohol and then silylation, afforded good yields ( approximately 70-75%) of the cis-2-alkyl-3-silyloxycycloalkanones B, presumably via the intermediates C and D, even with quite large alpha-substituents, e.g., tert-butyl. Finally, it has been shown that the stereochemistry of the epoxy alcohol is crucial as one would expect from the mechanism.