A simple method for avoiding alkylthio group migration during the synthesis of thioglycoside 2,3-orthoesters. An improved synthesis of partially acylated 1-thio-α-L-rhamnopyranosides

Article abstract of DOI:10.1016/0008-6215(92)80098-L

A fast, technically simple and high-yielding procedure is described for the preparation of the 2,3-cyclic orthoesters of methyl, ethyl, and phenyl 1-thio-α-L-rhamnopyranosides. The method prevents alkylthio group migration during the synthesis of thioglycoside 2,3-orthoesters. Considering the high yields, short reaction times and operational simplicity, this method is a substantial improvement over the procedures previously proposed for the synthesis of partially acylated 1-thio-α-L-rhamnopyranosides.