The [2+2] carbonylative cycloaddition of N-alfa-aza-heteroaryl substituted imines with allyl bromide led partially to beta-lactams, which underwent isomerization to the more stable alfa,beta-unsaturated carbonyl compound. Pyrimidinone derivatives together with doubly unsaturated amides represent the remaining isolated products. The strong electron-withdrawing effect of the two alfa-aza-heterocycles linked to the nitrogen atom and to the C4 of the 2-azetidinone structure could give a ring expansion, through a 2-azetinone intermediate that affords the pyrimidinone compounds. The substituted amides, instead, should result from a ring-opening reaction of the beta-lactam.
Synthesis and isomerization of N-alfa-aza-heteroaryl-beta-lactams
TROISI, Luigino;RONZINI, Ludovico;GRANITO, Catia;PINDINELLI, EMANUELA;
2006-01-01
Abstract
The [2+2] carbonylative cycloaddition of N-alfa-aza-heteroaryl substituted imines with allyl bromide led partially to beta-lactams, which underwent isomerization to the more stable alfa,beta-unsaturated carbonyl compound. Pyrimidinone derivatives together with doubly unsaturated amides represent the remaining isolated products. The strong electron-withdrawing effect of the two alfa-aza-heterocycles linked to the nitrogen atom and to the C4 of the 2-azetidinone structure could give a ring expansion, through a 2-azetinone intermediate that affords the pyrimidinone compounds. The substituted amides, instead, should result from a ring-opening reaction of the beta-lactam.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
