A synthetic approach to ( )-dioncophylline c

Abstract

In a synthetic approach to (+)-dioncophylline C (1), a coupling between the chiral oxazoline (3) and the Grignard reagent obtained from bromide (4) gave the major biaryl (5) and the minor biaryl (12) in good yield and high diastereoselectivity (yield 70%; ratio 91:9). The stereochemistry of the major biaryl (5) was confirmed by X-ray structure analysis of the derived crystalline iodide salt (13). © 1995 ASEG.