No abstract

No abstract

No abstract

The reactivity of the β-lactam ring towards nucleophiles has been investigated. Ring-opening reactions were performed on 3-allyl-β-lactams with CH 3 O -/CH 3 OH at room temperature and/or reflux. Lactam nucleus isomerization followed by N1-C2 bond cleavage and methanol Michael addition afforded substituted amino esters. The reactivity of the four-

Allyl halides of different structures, under CO pressure, in the presence of Et3N, a catalytic amount of Pd(OAc)2, and triphenylphosphane as ligand, undergo a [2+2] cycloaddition reaction with various imines. The reaction is highly regio‐ and stereoselective: β‐lactams are formed in good yields and with trans diastereoselectivity in both the β‐lactam ring and the vinylic moiety. New and important information is suggested regarding the known reaction mechanism. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)