A one-step photocatalytic synthesis of 2-(trifluoromethyl)butyrolactones

Abstract

An efficient one-step procedure is described for the synthesis of 2-(trifluoromethyl)butyrolactone 1 and 4-substituted 2-(trifluoromethyl)butyrolactones by the photocatalytic conjugate addition of primary and secondary alcohols to 2-(trifluoromethyl)acrylic acid 6. With the exception of methanol, the reactions are conducted without a photosensitiser. The diastereoisomers of compounds 8 and 10 were separable by chromatography and their relative configurations were established unambiguously by X-ray analyses of suitable crystals.