Total synthesis of (2S,3S,4R)-2-[(2′R)-2-benzoyloxydocosanoylamino]-16-methylheptadecane-1,3,4,-triol 3,4-dibenzoate, a partially protected ceramide part of sponge cerebrosides

Abstract

(2S,3S,4R)-2-[(2′R)-2-Benzoyloxydocosanoylamino]-16-methylheptadecane-1,3,4-triol 3,4-dibenzoate 32, a partially protected ceramide part of a cerebroside from the marine sponge Halichondria japonica, has been synthesized from L-ascorbic acid, and its absolute stereochemistry has been determined. The key steps in the synthesis include the regioselective ring opening of chiral epoxide 5 with a 2-alkyl-2-lithio-1,3-dithiane and the introduction of a hydroxymethylene synthon using Dondoni's protocol to assemble C(1) and C(2) functionality.