The enantioselective Horner–Wadsworth–Emmons reaction of 2-fluoro-2- diethylphosphonoacetates with σ-symmetric prochiral 2-substituted-1, 3-dioxan-5-ones and 4-substituted-cyclohexanones was investigated by employing Sn (OSO2CF3) 2 and N- ethylpiperidine in the presence of an external chiral ligand,(S)-(−)-1-methyl-2-(1- piperidinomethyl) pyrrolidine. A chiral α-fluoro-α, β-unsaturated ester was obtained in up ...