Synthesis of threo-4,5-dihydroxy diastereomers of sphinganine;

The threo-4,5-dihydroxy diastereomers of sphinganine were prepared by the following sequence of reactions: (a) benzoylation of sphingenine to the tribenzoyl derivative; (b) osmylation followed by resolution of the mixture of threo-4,5-dihydroxy tribenzoyl (DHTBS) diastereomers; and (c) alkaline hydrolysis to yield the threo-4,5-dihydroxysphinganines (DHS). Carbon atoms 4 and 5 of the high and low melting threo-4,5-DHTBS diastereomers and the compounds derived from them were tentatively assigned 4R, 5S and 5R configurations, respectively;