Bismuth nitrate-catalyzed synthesis of 3-pyrrole substituted monocyclic β-lactams

ORGN 476

Bimal K. Banik, banik@panam.edu1, Isabelle Salinas, banik@panam.edu2, and Hector Aguilar, banik@panam.edu1. (1) Department of Chemistry, The University of Texas-Pan American, 1201 W. University Drive, Edinburg, TX 78541, (2) Department of Chemistry, The Univeristy of Texas-Pan American, 1201 W. Univeristy Drive, Edinburg, TX 78541
Bismuth salts have become very popular in the synthesis of several organic compounds. There are a number of advantages of using bismuth salts. The use of bismuth salts in several organic transformations has received much attention. In particular, recently we have demonstrated a facile method for the synthesis of substituted pyrroles. During the course of this study and in continuation of our endeavor for the synthesis and biological evaluation of novel β-lactams, we develop a new pathway for the synthesis of novel β-lactams that have a pyrrole ring at the C-3 position of the azetidinone ring. The reaction of 3-keto β-lactams with commercially available 4-hydroxyproline in the presence of catalytic amounts of bismuth nitrate in ethanol produced a mixture of isomeric β-lactams with a pyrrole ring at the 3-position. Although the chemistry of β-lactams is extremely rich, preparation of pyrrole substituted azetidinones is not known. We are exploring a number of possibilities using the chemistry as described above.