4-Nitrobenzoyl chloride → 2,3,4-Tri-o-benzyl-1-o-p-nitrobenzoyl-alpha-l-fucopyranose

HRID 29736Notes

Reaction equation

HRID 29736 reaction equation
[CH2:1]([O:8][C@H:9]1[C@H:15]([O:16][CH2:17][C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=2)[C@H:14]([O:24][CH2:25][C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)[C@H:13]([CH3:32])[O:12][CH:10]1[OH:11])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[N+:33]([C:36]1[CH:44]=[CH:43][C:39]([C:40](Cl)=[O:41])=[CH:38][CH:37]=1)([O-:35])=[O:34]>C(Cl)Cl>[CH2:1]([O:8][C@H:9]1[C@H:15]([O:16][CH2:17][C:18]2[CH:19]=[CH:20][CH:21]=[CH:22][CH:23]=2)[C@H:14]([O:24][CH2:25][C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)[C@H:13]([CH3:32])[O:12][C@H:10]1[O:11][C:40](=[O:41])[C:39]1[CH:38]=[CH:37][C:36]([N+:33]([O-:35])=[O:34])=[CH:44][CH:43]=1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 85024-Nitrobenzoyl chloride2×HCID 2734155(3S,4R,5R,6S)-3,4,5-Tris(benzyloxy)-6-methyltetrahydro-2H-pyran-2-ol2×

Product 1

HCID 674131652,3,4-Tri-o-benzyl-1-o-p-nitrobenzoyl-alpha-l-fucopyranoseYield 80%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Since both the α and β isomers yielded the same β-bromide (compound 9), it was decided to skip the column purification and instead use the mixture as such. In this case, 2,3,4-tri-O-benzyl-L-fucopyranose (compound 6) (25 g, 55 mmol) was treated with p-nitrobenzoyl chloride (compound 7) as described above and the crude material (33.0 g) was dissolved in CH2Cl2 (100 mL) and simply filtered through a short column of silica gel. This removed the color and other polar material. This procedure furnished the anomeric mixture of esters (compound 8) as a gummy material (25.7 g, yield 80%).

Workup

  1. customthe column purification
  2. filtrationsimply filtered through a short column of silica gel
  3. customThis removed the color and other polar material
  4. customThis procedure furnished

Sources & evidence

ORD record
ord-eb77f61792b84d4e85c3a0623c96c0f5
Source dataset
uspto-grants-2008_09
Patent number
US07422733B2

Reaction notes

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