Sodium Bicarbonate → D-Glucosamine

Participants

Reaction Steps

The reaction mixture was poured over saturated sodium bicarbonate and saturated sodium thiosulfate aqueous solution (1:1,150 ml) contained in an Erlenmeyer flask and thoroughly stirred. Additional methylenechloride (100 ml) was added and the contents were thoroughly mixed for 10 min, the aqueous solution separated, and the organic layer washed sequentially with 10% aqueous sodium thiosulfate solution, 1% aqueous bleach solution, and aqueous saturated sodium bicarbonate solution. The solution was dried and concentrated. The resultant solid was dissolved in ethylacetate (200 ml) forming a colloidal suspension and hexane (200 ml) was slowly added. The precipitate was filtered and the process was repeated once more and finally, the precipitate was filtered and washed with EtOAc—Hexane (1:1) and dried under high vacuum over the weekend. Weight of the residue, product 23, was 21.4 g. 1H-NMR (CD2Cl2) δ (only select hydrogen chemical shifts are reported): 8.06-6.97 (phthalimido and benzoate hydrogens), 5.97, 5.76, 5.70 (H-3s of glucosamine unit), 3.72 (H-4 of the terminal glucosamine unit), 4.57 (H-6 of the reducing end glucosamine unit), 3.32 (OCH3), 0.62 (t-butyl), −0.21, −0.37 (2×CH3 of the silicon unit). MALDI data.: m/e calc. 4641.26 (100%); Obs. M+Na=4662.7. Thus the NMR and MALDI spectra verified the structure of product 23, as shown above.

Provenance & Evidence