摘要:
Schiff bases derived from (+/-)-4-aldehydo-2-azetidinones react with acid chlorides and triethylamine to produce (+/-)-bis-beta-lactams in a diastereoselective fashion. The steric course of beta-lactam formation was determined in one case by using chiral HPLC separation of enantiomers. Definitive evidence in support of this enantiospecific course of beta-lactam formation was obtained from single crystal X-ray diffraction studies on a racemic bis-beta-lactam.