Carbonyl Homologation via β-Trimethylsilyl β-Lactone Rearrangements. A Nonbasic Alternative to the Wittig Reaction

Abstract
Saturated and unsaturated aldehydes and ketones, when treated with trimethylsilylketene and BF3 for 16 hours, form β-lactones which spontaneously rearrange to α,β-unsaturated TMS esters; these hydrolyze during workup to form the corresponding carboxylic acids.