Patent ID: 7129355

Claim:
A process for preparing a compound of formula (I), or a salt thereof: where R 1 and R 2 are each independently protecting groups which, together with the oxygen atoms to which they are attached, form part of a dioxane or dioxolane ring; and R 3 is hydrogen or a protecting group; including the steps of: (a) protecting the hydroxyl group at the C-6 position of N—acetyl-D-mannosamine, to give a 6—O—protected—N—acetyl-D-mannosamine, wherein the hydroxyl protecting group at the C-6 position is selected from the group consisting of a silyl group, a benzyl group, or an ester group; (b) reducing the C-1 anomeric carbon atom of the 6—O—protected—N—acetyl-D-mannosamine using a reducing agent selected from the group consisting of a metal hydride reducing agent or hydrogen gas/metal catalyst to give a 6—O—protected —N—acetyl-D-mannitol; (c) protecting the four hydroxyl groups of the 6—O—protected—N—acetyl-D-mannitol with protecting groups R 1 and R 2 as defined above; (d) removing the N—acetyl protecting group using basic conditions and optionally removing the C-6 oxygen atom protecting group using basic conditions to give the compound of formula (I).