Synthesis of Benzoylated β-d-Glucosamine Derivatives

The preparation of intermediates for synthesis of d-glucosamine (2-amino-2-deoxy-d-glucopyranose) derivatives is of interest. The synthesis of 1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy-β–d-glucopyranose hydrochloride, described originally by Bergmann and Zervas ¹ in 1931, is often used to prepare glucosamine derivatives. ^2,3 This includes preparation of compounds for screening for medical applications where d-glucosamine is a core scaffold. ⁴ The analogous preparation of 2-amino-2-deoxy-1,3,4,6-tetra-O-benzoyl-β–d-glucopyranose hydrochloride 4 and its acetamide derivative 5, is also of interest. For example, the use of benzoates instead of acetate protecting groups in carbohydrate chemistry can lead to an enhancement in the rate of anomerization reactions, ⁵ and lead to increased yields from such reactions. ⁶ It can therefore be envisaged that 4 and 5 will be useful intermediates and we describe their preparation on multi-gram scale herein.