Intramolecular Dehydration of Dialkylacetic Acids and Trimethylsilylacetic Acid with Dicyclohexylcarbodiimide to the Corresponding Stable Ketenes

Abstract

A new, simple preparation for stable dialkyl ketenes involving intramolecular dehydration of appropriately substituted acetic acids with dicyclohexylcarbodiimide (DCC) in the presence of catalytic amounts of triethylamine gives 60-70% yield of the corresponding ketenes. Trimethylsilylacetic acid also gives trimethylsilylketene in good yield.