Stereoselective synthesis of thymine polyoxin C using an allylic trifluoroacetimidate–trifluoroacetamide rearrangement

Abstract

A stereoselective synthesis of thymine polyoxin C 3 is described in which the key step is the [3,3] sigmatropic rearrangement of the trifluoroacetimidate 12 to the trifluoroacetamide 13. Exchange of the protecting groups followed by ozonolysis and further oxidation then gave the methyl ester 20 which was converted into thymine polyoxin C 3 by introduction of the pyrimidine followed by final deprotection.