New, diastereoselective synthesis of 1-alkyl-5-alkylidene-3-methylidenepyrrolidin-2-ones

The diastereoselective synthesis of 1-alkyl-5-alkylidene-3-methylidenepyrrolidin-2-ones was readily accomplished in a two-step reaction sequence consisting of the reaction of 2-diethoxyphosphoryl-4-oxoalkanoates with amines followed by Horner-Wadsworth-Emmons olefination of formaldehyde using the intermediate 1-alkyl-5-alkylidene-3-diethoxyphosphorylpyrrolidin-2-ones.