Synthesis of glycosphingolipids from the fungus Hirsutella rhossiliensis

The total synthesis of two neutral glycosphingolipids (GSLs) from the fungus Hirsutella rhossiliensis has been achieved. The GSLs possess a common neogala-core (Galβ1-6Gal) and have the following sequence: α-d-Manp(1 → 3)-β-d-Galp(1 → 6)-β-d-Galp(1 → 6)-β-d-Galp(1↔1)Cer (1) and α-d-Manp(1 → 3)-β-d-Galp(1 → 6)[α-d-Glcp(1 → 4)]-β-d-Galp(1 → 6)-β-d-Galp(1↔1)Cer (2). Our efficient synthetic strategy uses the different reactivity of the hydroxyl groups of galactose and the α-orienting solvent effect of dioxane-toluene to generate GSLs (1) and (2).