Efficient synthesis of D-erythro-sphingosine and D-erythro-azidosphingosine from D-ribo-phytosphingosine via a cyclic sulfate intermediate

The synthesis of naturally occurring D-erythro-sphingosine and synthetically useful D-erythro-2-azidosphingosine from commercially available D-ribo-phytosphingosine is described. An important feature of this synthesis is the selective transformation of the 3,4-vicinal diol of phytosphingosine into the characteristic E-allylic alcohol of sphingosine via a cyclic sulfate intermediate.