Immunomodulating glycosphingolipids:: an efficient synthesis of a 2′-deoxy-α-galactosyl-GSL

A new and efficient approach to the total synthesis of 2'-deoxy-alpha-galactosyl glycosphingolipids was accomplished. Commercially available 3,4,6-tri-O-acetylgalactal was used as the chiral starting material for both the sugar and phytosphingosine building blocks required for the synthesis of 1-O-(2-deoxy-alpha-D-galactopyranosyl)-2-docosanoylamino-1,3,4-octadecanetriol. The key step of the synthetic strategy was the stereoselective alpha-glycosidation of the azido precursor of sphingosine. (C) 2002 Elsevier Science Ltd. All rights reserved.