Direct ketalisation of vic. - diols with hexafluoroacetone. Conversion of d-glucose and l-rhamnose derivatives to hexafluoroacetone ketals
作者:Ralf Miethchen、Daniel Rentsch、Norbert Stoll
DOI:10.1016/s0040-4020(01)86588-1
日期:1992.9
The cyclic hexafluoroacetone ketals and of the title compounds and were prepared with hexafluoroacetone (HFA) in the presence of dicyclohexylcarbodiimide (DCC). The reaction of 1,2-O-isopropylidene-α-d-glucofuranose with HFA leads without DCC addition only to a mixture of unstable hemiketals. This mixture of hemiketals was methylated with diazomethane and the corresponding methylketals were separated