| abstract |
enolates of 4-fluoro-2-hydroxymethylene-3-oxobutyrates of formula (I), wherein R 1 is C 1-10 alkyl, R 2 and R 3 are independently hydrogen or Fluorine, M is an alkali metal or an alkaline earth metal, and n is 1 or 2, is prepared from the corresponding enolate of 4-fluoro-3-oxobutyrates and carbon monoxide. Enolates of formula I can be alkylated or acylated to give the corresponding enol ethers and enol esters. The starting material 4-fluoro-3-oxobutyrate can be prepared by SbF5 -catalyzed elimination of fluoromethane from 1,1-difluoroethylmethyl ether followed by halogen exchange with lithium chloride to convert The resulting fluoroacetyl chloride is reacted with ketene, and the reaction is quenched with the appropriate alcohol R1 -OH. |