The cyclic sulphamidites (2S,4S)- and (2R,4S)-3-benzyl-4-benzyloxymethyl-2-oxo-1,2,3-oxathiazolidine 1 were prepared from S-glycidol in 60-66% overall yield. Nucleophilic ring opening of 1 by cyanide, azide and benzyloxy anions have been studied with respect to regio and stereospecificity. A mild procedure for benzylation of alcohols was introduced.
Synthesis of the (α,α-difluoroalkyl)phosphonate analogue of phosphoserine
作者:David B. Berkowitz、Quanrong Shen、Jun-Ho Maeng
DOI:10.1016/s0040-4039(00)78242-6
日期:1994.8
The synthesis of the (alpha,alpha-difluoroalkyl)phosphonate analogue of L-phosphoserine, 5, in a form appropriate for solid phase peptide synthesis, is reported. Two independent routes are described, starting from L-serine or (R)-isopropylideneglycerol. In each case, PCF2-C bond formation is achieved by triflate displacement with diethyl lithiodifluoromethylphosphonate.