A concise synthesis of (3S,4S,5R)-1-(α-d-galactopyranosyl)-3-tetracosanoylamino-4,5-decanediol, a C-glycoside analogue of immunomodulating α-galactosylceramide OCH

A concise and convergent synthesis of the C-glycoside analogue 2b of immunomodulating α-galactosylceramide OCH 1b starting from readily available 2,3,4,6-tetra-O-benzyl-d-galactose 3 and l-arabinose 6 is described. The synthesis features the nucleophilic addition of an α-ethynyl sugar 5 to the phytosphingosine-precursor aldehyde 9 and would be applicable to a variety of C-glycoside analogues of interest.