‡ These authors contributed equally to this work.
A new efficient synthesis of pyrrolidin-2-ones via sequential Wittig reaction/nucleophilic addition/cyclization was developed. The Wittig reaction of the phosphoranes with isocyanates produced ketenimine intermediates that were then treated with primary amines to give amidines, which were treated with catalytic sodium alkoxide to give 2-imino-5-oxopyrrolidine-3-carboxylates in good yields.
Key words
pyrrolidin-2-one - Wittig reaction - ketenimine - amidine - isocyanate