Efficient synthesis of d-xylo and d-ribo-phytosphingosines from methyl 2-amino-2-deoxy-β-d-hexopyranosides

A general and flexible synthetic approach to biologically important 5,6-unsaturated C18-phytosphingosines was developed via olefin cross-metathesis employing truncated C6-phytosphingosines as the key intermediates. These were efficiently prepared in high yields by zinc-mediated reductive opening of methyl 2-amino-2-deoxy-β-hexopyranosides.