Aq. Chen et al., Stereoselective synthesis of thymine polyoxin C using an allylic trifluoroacetimidate-trifluoroacetamide rearrangement, J CHEM S P1, (22), 1999, pp. 3305-3310
A stereoselective synthesis of thymine polyoxin C 3 is described in which t
he key step is the [3,3] sigmatropic rearrangement of the trifluoroacetimid
ate 12 to the trifluoroacetamide 13. Exchange of the protecting groups foll
owed by ozonolysis and further oxidation then gave the methyl ester 20 whic
h was converted into thymine polyoxin C 3 by introduction of the pyrimidine
followed by final deprotection.