Studies toward the synthesis of the rifamycin S polypropionate chain

ORGN 629

David Rodriguez, Marlenne Mulero, and José A. Prieto. Department of Chemistry, University of Puerto Rico, PO Box 23346, San Juan, PR 00931-3346
Rifamycin S is a member of the ansamycin antibiotics. It has been studied as a possible treatment for arthritis disorders and as a potential anti-inflammatory drug. This macrocycle has connected an aliphatic chain with an aromatic portion. The aliphatic portion, the ansa chain, which constitutes the focus of this study, has eight consecutives stereogenic centers alternating methyl and oxygenated substituent, the polypropionate chain. We are currently working on the stereoselective preparation and regioselective cleavage of epoxides. In this study, precursor alkenes are converted to their corresponding epoxide, which finally are cleaved by alkynyl alanes or Grignard reagents to generate the C-C bonds and the propionate unit. The incorporated alkene is transformed into another epoxide and cleaved with another carbon nucleophile in a reiterative fashion to construct the polypropionate chain avoiding the stereochemical problem encountered in some aldol methodologies.

 

New Reactions, Methodology, Heterocycles, Aromatics
8:00 PM-10:00 PM, Wednesday, August 25, 2004 Pennsylvania Convention Center -- Hall D, Poster

Division of Organic Chemistry

The 228th ACS National Meeting, in Philadelphia, PA, August 22-26, 2004