Acetone → HCID 54047185, compound

Participants

Reaction Steps

A solution of crude 17 in the minimum amount of dichloromethane was stirred at room temperature with aqueous 80% acetic acid (100 mL) until TLC demonstrated the disappearance of 17. Water was then added with stirring; the solid was removed and the filtrate was concentrated. The crude 3-O-benzyl-1,2,4-tri-O-acetyl-D-glucopyranose (18) was thus obtained; 1H NMR data: 60:40 mixture of anomers 6.32 (d, 1 H, alpha-H), 5.64 (d, 1 H, beta-H). A solution of the crude residue 18 in acetone was cooled to -5° C. and a solution of chromium trioxide in 3.5M sulfuric acid was added dropwise with stirring. The mixture was allowed to attain room temperature, and, after 5 hours at room temperature, was poured into ice-cold water and extracted with chloroform. The extract was washed with water and concentrated, and a solution of the crude methyl ester of 3-O-benzyl-1,2,4-tri-O-acetyl-D-glucopyranosuronic acid (19) in ether was esterified with ethereal diazomethane. The product was eluted from a column of silica gel with chloroform-ethyl acetate (20:10) to give 19 (54%). 1H NMR date: mixture of anomers alpha:beta=60:40; 7.23-7.36 (m, 5 H, arom.), 6.38 (d, 1 H, alpha-H), 5.69 (d, 1 H, beta-H), 3.72 (s, 3 H, alpha-COOMe), 3.71 (s, 3 H, beta-COOMe), 1.96-2.16 (9 H, Ac).

Provenance & Evidence