Synthesis of 2-Carboxy-Substituted Sphingosine Derivatives

From the sphingosine biosynthesis pathway it is deduced that 2-carboxy-substituted sphinganine derivatives should be suitable inhibitors of sphingosine biosynthesis. For their synthesis enantioselective acylation and α-hydroxyalkylation of serine was performed via its optically pure 2-tert-butyl-oxazolidine derivatives 4A, B and ent-4A, known to undergo partial chirality transfer from serine to the 2- position of 4 and then to the 4-position. Thus, after acid hydrolysis compounds R-7Aa, -7Ab, -7Ac, -7Bb, S -7Aa, -7Ab, and 11 are provided highly stereoselectively.