Synfacts 2008(3): 0241-0241  
DOI: 10.1055/s-2008-1042742
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Substituted Pyrroles from 2-Azetidinone Allenols

Contributor(s): Victor Snieckus, Johnathan Board
B. Alcaide*, P. Almendros, R. Carrascosa, M. C. Redondo
Universidad Complutense de Madrid, Spain
Further Information

Publication History

Publication Date:
21 February 2008 (online)


Reported is the formation of highly substituted pyrrole systems by reaction of β-lactams with sodium methoxide. The required β-lactams were formed through an indium-mediated Barbier-type allenylation reaction previously developed by the authors. Reaction of these allenyl β-lactams with sodium methoxide opens the lactam ring to a secondary amine, which then undergoes reaction with the allene to form the desired pyrrole ring upon workup. Two examples of the intermediate amine (structures A above) were isolated and cyclized to pyrroles using catalytic silver nitrate. All other analogues examined spontaneously formed pyrroles under the sodium methoxide reaction conditions.