including proliferation, survival, and migration. For this reason the stereoselective syntheses of S1P and analogues are of great interest. Based on l-serine as source of chirality we achieved practical routes to prepare S1P (1) and the aryl group containing analogues 3 and 4 in fair amounts. The crucial stages of the syntheses are: introduction of the required side chain by addition of appropriate organometallics
preparation of aryl and heteroaryl ceramide analogues 2 and 3. The first route involves the addition of an aryllithium or a heteroaryllithium reagent (7a or 25a, respectively) to the L-serine-derived aldehyde 4, followed by hydrolysis of the oxazolidine, liberation of the amino group, and N-acylation. The second route, which was used to prepare arylceramide analogue 2 in eight steps and 28% overall yield starting