Benzyl b-D-galactopyranoside

• CAS: 14897-46-2
• Catalog Number: ACM14897462
• Category: Main Products
• Molecular Weight: 270.28
• Molecular Formula: C₁₃H₁₈O₆
• Synonyms: Benzyl D-Glucopyranoside; Mannopyranoside,benzyl (7CI); Phenylmethyl a-D-mannopyranoside; Phenylmethyl D-Glucopyranoside; Mannopyranoside,benzyl,a-D-(8CI); Benzyl |A-D-Mannopyranoside
• IUPAC Name: (2R,3R,4S,5R,6R)-2-(hydroxymethyl)-6-phenylmethoxyoxane-3,4,5-triol
• Canonical SMILES: C1=CC=C(C=C1)COC2C(C(C(C(O2)CO)O)O)O
• InChI Key: GKHCBYYBLTXYEV-KSSYENDESA-N
• Exact Mass: 270.11000

Case Study

Regioselective Acylation of Benzyl β-D-Glucopyranoside

Gonçalves, Pedro ML, et al. Tetrahedron, 2004, 60(4), 927-932.

The α- and β-anomers of glucopyranosides and galactopyranosides can be separated by enzymatic regioselective acylation. Benzyl β-D-glucopyranoside (14) was made from β-glucose (43%), with β-glucosidase of almonds. This is then used to make benzyl 6-O-butyryl β-D-glucopyranoside (21). Here is the synthèse process:
· Benzyl β-D-glucopyranoside (14)
Add 120 mg of almond β-glucosidase to D-glucose (0.81 g, 4.48 mmol) in distilled water (2 cm3) and benzyl alcohol (18 cm3). Mixture was agitated for 30 hours at 50°C and the enzyme was filtrate and washed in distilled water (5 cm3). Excess benzyl alcohol was evaporated under less pressure at 90°C and 1 mbar. The residue was filtered by flash chromatography on silica in chloroform-methanol (9:1) eluent, resulting in compound 14 (0.52 g, 43%) as a white solid.
· Benzyl 6-O-butyryl β-D-glucopyranoside (21)
0.10 g of Novozyme 435 was added to dry THF (10 cm3) containing benzyl β-D-glucopyranoside (14) (0.31 g, 1.14 mmol) and vinyl butyrate (0.3 cm3, 2.36 mmol). The mix was then in an oil bath and stirred at 60°C. The reaction took 3 hours (till TLC indicated it had been completed) and the mix was removed to room temperature. The solvent was then evaporated at reduced pressure. This residue was flash chromatographed on silica with an ethyl acetate-ethanol (95:5) eluent, and compound 21 was recovered as a white solid (0.38 g, 98%).