Donald F. Sullivan

O-Silylation and Attempted O-Alkylation of Lithium Ester Enolates. The Synthesis of O-Silyl Ketene Acetals

Abstract The reaction of ketone enolates with alkylating or silylating reagents can be used to prepare O-alkyl or O-silyl vinyl ethers1. An analogous reaction of ester enolates would produce O-alkyl (I) or O-silyl (II) ketene acetals2. Such a simple route to ketene acetal structures would appear to be of major synthetic value3. Consequently, we have studied the reaction of lithium ester enolates, obtained from the corresponding esters and lithium N-isopropylcyclohexylamide (LiICA)4 as shown in eq. 1, with a variety of alkylating and silylating reagents.