Acetic Anhydride → allyl 2-acetamido-3,4-di-O-acetyl-2-deoxy-6-O-tolylsulfonyl-alpha-D-mannopyranoside

HRID 962425Notes

Reaction equation

HRID 962425 reaction equation
[C:1]([NH:4][C@H:5]1[C@@H:14]([O:15][C:16](=[O:18])[CH3:17])[C@H:13]([O:19][C:20](=[O:22])[CH3:21])[C@@H:12]([CH2:23][O:24]C(=O)C)[O:11][C@@H:6]1[O:7][CH2:8][CH:9]=[CH2:10])(=[O:3])[CH3:2].C[O-].[Na+].[C:31]1([CH3:41])[CH:36]=[CH:35][CH:34]=[CH:33][C:32]=1[S:37](Cl)(=[O:39])=[O:38].C(OC(=O)C)(=O)C>CO.N1C=CC=CC=1.C(Cl)Cl>[C:1]([NH:4][C@H:5]1[C@@H:14]([O:15][C:16](=[O:18])[CH3:17])[C@H:13]([O:19][C:20](=[O:22])[CH3:21])[C@@H:12]([CH2:23][O:24][S:37]([C:32]2[CH:33]=[CH:34][CH:35]=[CH:36][C:31]=2[CH3:41])(=[O:39])=[O:38])[O:11][C@@H:6]1[O:7][CH2:8][CH:9]=[CH2:10])(=[O:3])[CH3:2]

Participants

8

Reactant 4

HCID 7918Acetic AnhydrideHCID 8623o-Toluenesulfonyl chlorideHCID 10942334Sodium MethoxideHCID 13968146allyl 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-alpha-D-mannopyranoside

Product 1

HCID 86749068allyl 2-acetamido-3,4-di-O-acetyl-2-deoxy-6-O-tolylsulfonyl-alpha-D-mannopyranosideYield 44%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 1049PyridineSolvent2×HCID 6344DichloromethaneSolvent2×

Procedure

A solution of allyl 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-D-mannopyranoside, prepared as described above, (6.46 g, 16.7 mmol) and methanolic NaOMe (2 mL; 1M solution) in MeOH (100 mL) was stirred for two hours at room temperature, and neutralized by addition of Dowex 50W-X8 [H+]. After the resin was filtered off, the filtrate was concentrated followed by coevaporation with pyridine. A solution of tolylsulfonyl chloride (3.50 g, 18.3 mmol) in pyridine (20 mL) and CH2Cl2 (30 mL) was added dropwise to a cooled solution of the residue in pyridine (30 mL) and CH2Cl2 (50 mL) at 0°-5° C. over 30 minutes, and the mixture was stirred for 10 hours at room temperature then cooled. Acetic anhydride (30 mL) was added to the mixture, and the mixture was stirred for five hours at room temperature. The mixture was concentrated, and the residue was chromatographed on silica gel, with toluene-EtOAc (1:2), to give allyl 2-acetamido-3,4-di-O-acetyl-2-deoxy-6O-tolylsulfonyl-α-D-mannopyranoside (3.68 g, 44%);

Workup

  1. additionneutralized by addition of Dowex 50W-X8 [H+]
  2. filtrationAfter the resin was filtered off
  3. concentrationthe filtrate was concentrated
  4. temperaturethen cooled
  5. stirringthe mixture was stirred for five hours at room temperature
  6. concentrationThe mixture was concentrated
  7. customthe residue was chromatographed on silica gel, with toluene-EtOAc (1:2)

Sources & evidence

ORD record
ord-66e8742b4a6f4f76915dacf36e6eef53
Source dataset
uspto-grants-1998_06
Patent number
US05759823

Reaction notes

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