3-O-Benzyl-1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose → 3-O-Benzyl-1,2-O-isopropylidene-alpha-D-glucofuranose

HRID 2050661Notes

Reaction equation

HRID 2050661 reaction equation
CC1(C)[O:6][CH:5]([CH:7]2[O:11][CH:10]3[O:12][C:13]([CH3:16])([CH3:15])[O:14][CH:9]3[CH:8]2[O:17][CH2:18][C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[CH2:4][O:3]1>CO.C(O)(=O)C.O>[CH3:15][C:13]1([CH3:16])[O:12][C@@H:10]2[C@@H:9]([C@@H:8]([O:17][CH2:18][C:19]3[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=3)[C@@H:7]([C@H:5]([OH:6])[CH2:4][OH:3])[O:11]2)[O:14]1

Participants

5

Reactant 1

HCID 979073-O-Benzyl-1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose

Product 1

HCID 110881883-O-Benzyl-1,2-O-isopropylidene-alpha-D-glucofuranoseYield 87%

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 887MethanolSolventHCID 962WaterSolvent

Procedure

Crude 3-O-benzyl-1,2:5,6-di-O-isopropylidene-α-D-glucofuranose (6) (23.5 g, 75.6 mmol) was dissolved in a 1:1:1 mixture of methanol, acetic acid and water (200 ml) and stood at 50° C. for 16 hours. The solvents were evaporated and the crude syrup purified by flash chromatography (ethyl acetate-hexane 3:2) to give 3-O-benzyl-1,2-O-isopropylidene-α-D-glucofuranose (18.1 g, 87%) as a clear oil, [α]20D -49.9° (c, 1.08 in chloroform) [lit.44 -50.8° (c, 1.24 in chloroform)]; 1H NMR δ 1.33, 1.49 (6H, 2×s, acetonide); 2.17 (2H, bs, 2×OH); 3.69, 3.81 (2H, 2×dd, H-6,6', J6,6' 11.4 Hz, J5,6 5.5 Hz, J5,6' 3.4 Hz); 4.00-4.15 (3H, m, H-3, H-4, H-5); 4.56, 4.73 (2H, 2×d, CH2Ph, JH,H' 11.7 Hz); 4.63 (1H, d, H-2); 5.94 (1H, d, 1-H,J1,2 3.7 Hz); 7.31-7.38 (5H, m, H-Ph).

Workup

  1. customThe solvents were evaporated
  2. customthe crude syrup purified by flash chromatography (ethyl acetate-hexane 3:2)

Sources & evidence

ORD record
ord-926aa6f1afec4d9c93b36861300c761d
Source dataset
uspto-grants-1991_05
Patent number
US05013842

Reaction notes

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