(6c) with TFA in THF, however, afforded, after distillation, a mixture of products, of which the minor compound was the trifluoroacetylated compound 7c. After column chromatography (alumina), the major reaction product, a white crystalline compound, was isolated in a yield of 53%. Mass spectrometry and elemental analysis exhibited that a CF3C0 moiety had been introduced, but the absence of a carbonyl group (IR and I3C NMR spectroscopy) ruled
