We have developed a versatile new synthesis of the Ψ [CH2O] pseudopeptides from N- protected-5-substituted morpholin-3-ones. The morpholin-3-ones are prepared in two steps from the corresponding amino alcohols by treatment with ethyl chloroacetate, followed by protection of the amide. We found that direct alkylation of the protected morpholin-3-ones gives the expected alkylation product where the electrophile approaches from the face ...