摘要:
The enantiopure gamma-lactam (R)-1-acetyl-5-isopropoxy-3-pyrrolin-2-one (1), prepared from (S)-malic acid, undergoes cuprate addition at C4 with complete trans-stereoselectivity. The products react with pi-nucleophiles in the presence of Lewis acid at C5 to provide enantiopure 4,5-disubstituted pyrrolidin-2-ones.