Synthesis and Stereochemical Assignment of FR252921, a Promising Immunosuppressant

Abstract

Synthetic detective work: FR252921, an unusual 19-membered lactone–dilactam, and three of its diastereomers were prepared by a versatile, convergent strategy from three key segments (see scheme). Comparison of the synthetic compounds with natural material established conclusively that FR252921 has the configuration 12S,13R,18R. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2007/z700321_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.