Acetic Anhydride → Methyl 2-O-acetyl-3,5-di-O-benzyl-4-C-methanesulfonyloxymethyl-D-ribofuranoside

HRID 2100290Notes

Reaction equation

HRID 2100290 reaction equation
[CH2:1]([O:8][C@@H:9]1[C@@:15]([CH2:25][O:26][S:27]([CH3:30])(=[O:29])=[O:28])([CH2:16][O:17][CH2:18][C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[O:14][C@H:11]([O:12][CH3:13])[C@@H:10]1[OH:31])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:32](OC(=O)C)(=[O:34])[CH3:33]>N1C=CC=CC=1>[C:32]([O:31][C@@H:10]1[C@H:9]([O:8][CH2:1][C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=2)[C@@:15]([CH2:25][O:26][S:27]([CH3:30])(=[O:29])=[O:28])([CH2:16][O:17][CH2:18][C:19]2[CH:20]=[CH:21][CH:22]=[CH:23][CH:24]=2)[O:14][CH:11]1[O:12][CH3:13])(=[O:34])[CH3:33]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 20610801Methyl 3,5-di-O-benzyl-4-C-methanesulfonyloxymethyl-alpha-D-ribofuranoside

Product 1

HCID 11145450Methyl 2-O-acetyl-3,5-di-O-benzyl-4-C-methanesulfonyloxymethyl-D-ribofuranosideYield 100%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

To a stirred solution of 201 (687 mg, 1.52 mmol) in anhydrous pyridine (4 mL) at 0° C. was added dropwise acetic anhydride (0.43 mL, 4.56 mmol). The reaction mixture was stirred for 2 days at room temperature, quenched with saturated aqueous sodium hydrogen carbonate (75 mL) and extracted with dichloromethane (150+75 mL). The combined extract was dried (MgSO4), the solvent was removed by distillation under reduced pressure and the residue was purified by chromatography over silica gel with dichloromethane as eluent to give the product 209 as a clear oil (β:α˜3:1, 750 mg, 100%); MS FAB: 463 (M-OCH3, 100%), 517 (M+Na, 28%); Found: C, 58.53; H, 6.16; C24H30O9S requires C, 58.29; H, 6.11%. Methyl 2-O-acetyl-3,5-di-O-benzyl-4-C-methanesulfonyloxymethyl-β-D-ribofuranoside (209β). 1H NMR (CDCl3): δ 7.36-7.18 (10 H, m, Bn), 5.27 (1 H, d, J 4.9 Hz, H-2), 4.88 (1 H, s, H-1), 4.55-4.44 (6 H, m, H-5′, Bn), 4.35 (1 H, d, J 5.0 Hz, H-3), 3.73 (1 H, d, J 9.2 Hz, H-5), 3.38 (1 H, d, J 9.3 Hz, H-5), 3.30 (3H, s, OCH3), 2.95 (3 H, s, SO2CH3), 2.11 (3 H, s, OCCH3); 13C NMR (CDCl3): δ 169.91 (C═O), 137.83, 137.28, 128.49, 128.44, 127.99, 127.87, 127.77 (Bn), 105.40 (C-1), 82.65, 81.05, 74.55, 73.62, 73.56, 71.86, 70.22 (C-2, C-3, C-4, C-5, C-5′, Bn), 55.03 (OCH3), 37.14 (SO2CH3), 20.73 (OCCH3). Methyl 2-O-acetyl-3,5-di-O-benzyl-4-C-methanesulfonyloxymethyl-α-D-ribofuranoside (209α). 1H NMR (CDCl3): δ 7.36-7.18 (10 H, m, Bn), 5.09 (1 H, d, J 4.5 Hz, H-1), 4.95 (1 H, dd, J 4.5, 6.8 Hz, H-2), 4.65-4.44 (6 H, m, H-5′, Bn), 4.27 (1 H, d, J 6.6 Hz, H-3), 3.49 (1 H, d, J 9.9 Hz, H-5), 3.46 (3 H, s, OCH3), 3.36 (1 H, d, J 9.9 Hz, H-5), 2.92 (3 H, s, SO2CH3), 2.14 (3 H, s, OCCH3); 13C NMR (CDCl3): δ 170.41 (C═O), 137.59, 137.28, 128.56, 128.51, 128.49, 128.44, 127.98, 127.88 (Bn), 102.35 (C-1), 84.25, 77.53, 74.66, 73.67, 72.12, 70.39, 70.28 (C-2, C-3, C-4, C-5, C-5′, Bn), 56.07 (OCH3), 36.94 (SO2CH3), 20.63 (OCCH3).

Workup

  1. customquenched with saturated aqueous sodium hydrogen carbonate (75 mL)
  2. extractionextracted with dichloromethane (150+75 mL)
  3. extractionThe combined extract
  4. dry with materialwas dried (MgSO4)
  5. customthe solvent was removed by distillation under reduced pressure
  6. customthe residue was purified by chromatography over silica gel with dichloromethane as eluent

Sources & evidence

ORD record
ord-720d0f948f2f47c4b2fc777146ac9d26
Source dataset
uspto-grants-2009_08
Patent number
US07572582B2

Reaction notes

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