SYNTHESIS OF CYCLIC AND ACYCLIC ENOL ETHERS (VINYL ETHERS)

A general method has been developed for the conversion of both cyclic and acyclic acetals of cyclic ketones, acyclic ketones, and aldehydes into enol ethers through treatment of the acetal with trimethylsilyl triflate in the presence of N,N-diisopropylethylamine. The range of isolated yields of enol ethers from the various classes of acetals was as follows: cyclic acetals of cyclic ketones, 83-98%; acyclic acetals of ketones, 72-94%; acyclic and cyclic acetals of aldehydes, 65-90%.