Asymmetric synthesis of vicinal amino alcohols: xestoaminol C, sphinganine and sphingosine

The highly diastereoselective anti-aminohydroxylation of alpha,beta-unsaturated esters, via conjugate addition of lithium (S)-N-benzyl-N-(alpha-methylbenzyl) amide and subsequent in situ enolate oxidation with (+)-(camphorsulfonyl) oxaziridine, has been used as the key step in the asymmetric synthesis of N,O-diacetyl xestoaminol C(41% yield over 8 steps), N,O,O- triacetyl sphinganine (30% yield over 8 steps) and N,O,O-triacetyl sphingosine (30% yield over 7 steps).