A concise enantioselective synthesis of N -morpholinosphingosines from D -aspartic acid

D-Aspartic acid, by N-tosylation, anhydride formation, reduction, α-hydroxylation and iodo-esterification, gives ethyl (2R,3R)-3-[(N-tosyl)amino]-2-hydroxy-4-iodobutyrate which, by treatment with morpholine, silylation, DIBAH reduction, Wittig reaction and deprotection, gives the N-morpholinosphingosine 13 in an overall yield of 27%.