Methyl 3,3-difluoro-2-trimethylsilyloxyacrylate: preparation and Mukaiyama-type aldol condensation as a novel route to β,β-difluoro-α-keto ester derivatives

Mukaiyama-type aldol condensation of arylaldehyde acetals occurs smoothly with methyl 3,3-difluoro-2-trimethylsilyloxyacrylate (derived from ethyl 3,3-difluoro-2-benzoylacrylate) when catalyzed by a Lewis acid, allowing preparation of 4-alkyloxy-3,3-difluoro-2-keto esters in high yields.