HCID 66607994, compound → HCID 58242574, compound

Participants

Reaction Steps

3-(4-ethylphenylmethyl)-2,4-pentanedione 28 (700 mg) and 2,3,4,6-tetra-O-benzyl-α,β-D-glucosehydrazone 29 (1.70 g) (See Schmidt, R. R. et al., Liebigs Ann. Chem. 1981, 2309) were dissolved in tetrahydrofuran (20 ml), and the mixture was stirred at room temperature for 18 hours under argon atmosphere. The solvent was evaporated under reduced pressure, and the residue was dissolved in toluene (20 ml), and the mixture was heated with stirring under reflux for 2 hours. The mixture was left alone until it was cooled, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=90:10-65:35) to give 3,5-dimethyl-4-(4-ethylphenylmethyl)-1-(2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl)pyrazole 30 (299 mg) as a pale yellow semisolid. APCI-Mass m/Z 737 (M+H). (2) The above tetrabenzyl compound 30 (294 mg) was dissolved in a mixture of ethanol (5 ml) and tetrahydrofuran (4 ml), and added thereto was palladium hydroxide (100 mg), and the mixture was stirred at room temperature for 16 hours under hydrogen atmosphere under normal pressure. Insoluble materials were filtered off, and the solvent was evaporated under reduced pressure. The residue was crystallized from diethyl ether to give the desired 3,5-dimethyl-4-(4-ethylphenylmethyl)-1-(β-D-glucopyranosyl)pyrazole 31 (118 mg) as colorless powder. APCI-Mass m/Z 377 (M+H).

Provenance & Evidence