Hydrochloric Acid → (3S,4R,5S,6R)-3-amino-6-(hydroxymethyl)oxane-2,4,5-triol hydrochloride

Participants

Reaction Conditions

Reaction Steps

To 12.0 g of N-benzyl-mannosamine of example 2A was added a suspension of 10% Pd/C (0.5 g) in 20 ml water. The pH of the reaction mixture was adjusted to 4-4.5 with 10% HCl solution. The reaction mixture was stirred for 6 hours at 40° C. under H2 pressure (2.5 bar). The pH was then adjusted to 3 with 10% HCl solution. The reaction mixture was kept unstirred overnight so that the catalyst could settle down (the catalyst remains in the reactor). The catalyst was filtered off and washed with a small amount of methanol:water (2:1). The methanol was removed in vacuo and replaced by 15 mL isopropanol. The isopropanol was distilled off and the same procedure was repeated again. To the reaction mixture, 30 ml iPrOH was added and the product crystallized overnight at 4° C. The crystals were filtered and washed with 5-8 mL isopropanol. The wet product was dried at room temperature, to give 8.4 g of D-mannosamine hydrochloride.

Provenance & Evidence