Preparation of anti-Vicinal Amino Alcohols: Asymmetric Synthesis of D-erythro-Sphinganine, (+)-Spisulosine, and D-ribo-Phytosphingosine

Two variations of the Overman rearrangement have been developed for the highly selective synthesis of anti-vicinal amino alcohol natural products. A MOM ether-directed palladium(II)-catalyzed rearrangement of an allylic trichloroacetimidate was used as the key step for the preparation of the protein kinase C inhibitor D-erythro-sphinganine and the antitumor agent (+)-spisulosine, whereas the Overman rearrangement of chiral allylic trichloroacetimidates generated by the asymmetric reduction of an alpha,beta-unsaturated methyl ketone allowed rapid access both to D-ribo-phytosphingosine and L-arabino-phytosphingosine.