Preparation of α-fluoro-β-per(poly) fluoroalkyl-substituted enol ethers

Article abstract of DOI:10.1016/0022-1139(95)03382-3

Fluorocarboethoxymethylene tri-n-butylphosphorane, Bu₃P=CFCOOEt (3), reacts with per- and poly-fluoroalkyl-substituted carboxylic acid esters, ethyl formate and γ-butyrolactone to give the corresponding enol ethers, R_FC (OEt)=CFCOOEt (4), in good yield. Non-activated esters failed to react with 3. With the anion derived from ethyl diethylphosphonofluoroacetate, (EtO)₂P(O)CFHCOOEt (5), a mixture of 4 and β-ketoesters, R_FC(O)CFHCOOEt (7), is formed.