Tandem reduction-olefination for the stereoselective synthesis of (Z)-alpha-fluoro-alpha,beta-unsaturated esters

摘要

A tandem stereoselective reduction-olefination reaction of theyl 2-acyl-2-fluoro-2-diethylphosphonoacetate employing NaBH_4 in EtOH was developed.The one-pot reaction gave alpha-fluoro-alpha,beta-unsaturated esters with excellent (Z)-selectivity,A plausible mechanism involving a diastereoselective reduction predicted by the Felking-Anh model,followed by olefination similar to the Hormer-Wadsorth-Emmons reaction,has been proposed.