Facile syntheses of gem-difluoroalkenes from chlorodifluoromethylketones

Abstract

Chlorodifluoromethyl ketones reacted with diazomethane to afford epoxides in high yield; upon treatment with butyllithium, the epoxides underwent efficient ring opening to afford 3,3-difluoro-2-alkyl-alken-1-ols, suitable substrates for sigmatropic rearrangement leading to compounds containing a CF2 group in mid-chain.