2,4,6-Trimethylpyridine → Methyl 6-O-(4-O-acetyl-2,3,6-tri-O-benzyl-alpha-D-galactopyranosyl)-2,3,4-tri-O-benzyl-alpha-D-glucopyranoside

HRID 2372158Notes

Reaction equation

HRID 2372158 reaction equation
[CH2:1]([O:8][C@@H:9]1[C@@H:16]([O:17][CH2:18][C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[C@H:15]([O:25][CH2:26][C:27]2[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=2)[C@@H:14]([CH2:33][OH:34])[O:13][C@@H:10]1[O:11][CH3:12])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:35]([O:38][C@H:39]1[C@@H:44]([CH2:45][O:46][CH2:47][C:48]2[CH:53]=[CH:52][CH:51]=[CH:50][CH:49]=2)[O:43][C@H:42](Cl)[C@H:41]([O:55][CH2:56][C:57]2[CH:62]=[CH:61][CH:60]=[CH:59][CH:58]=2)[C@H:40]1[O:63][CH2:64][C:65]1[CH:70]=[CH:69][CH:68]=[CH:67][CH:66]=1)(=[O:37])[CH3:36].CC1C=C(C)C=C(C)N=1>CCOCC.Cl([O-])(=O)(=O)=O.[Ag+]>[C:35]([O:38][C@H:39]1[C@@H:44]([CH2:45][O:46][CH2:47][C:48]2[CH:53]=[CH:52][CH:51]=[CH:50][CH:49]=2)[O:43][C@H:42]([O:34][CH2:33][C@H:14]2[O:13][C@H:10]([O:11][CH3:12])[C@H:9]([O:8][CH2:1][C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=3)[C@@H:16]([O:17][CH2:18][C:19]3[CH:20]=[CH:21][CH:22]=[CH:23][CH:24]=3)[C@@H:15]2[O:25][CH2:26][C:27]2[CH:28]=[CH:29][CH:30]=[CH:31][CH:32]=2)[C@H:41]([O:55][CH2:56][C:57]2[CH:58]=[CH:59][CH:60]=[CH:61][CH:62]=2)[C@H:40]1[O:63][CH2:64][C:65]1[CH:66]=[CH:67][CH:68]=[CH:69][CH:70]=1)(=[O:37])[CH3:36]

Participants

6

Reactant 3

HCID 79532,4,6-TrimethylpyridineHCID 11190476Methyl 2,3,4-tri-O-benzyl-alpha-D-glucopyranosideHCID 544033654-O-acetyl-2,3,6-tri-O-benzyl-alpha-D-galactopyranosyl chloride

Product 1

HCID 53849711Methyl 6-O-(4-O-acetyl-2,3,6-tri-O-benzyl-alpha-D-galactopyranosyl)-2,3,4-tri-O-benzyl-alpha-D-glucopyranosideYield 55%

Reagents, catalysts & solvents 2

HCID 24562Silver perchlorateCatalystHCID 3283Diethyl EtherSolvent

Conditions

Temperature
-30 °C

Procedure

Ethereal silver perchlorate (0.08M, 76.9 mL, 6.15 mmol) was added with stirring at -30° C. to a solution of methyl 2,3,4-tri-O-benzyl-α-D-glucopyranoside (2.078 g, 4.48 mmol), 4-O-acetyl-2,3,6-tri-O-benzyl-α-D-galactopyranosyl chloride (2.859 g, 5.6 mmol) and 2,4,6-trimethylpyridine (0.81 mL, 6.15 mmol) in ether (20 mL). The mixture was stirred 15 min at -30° C. and silver chloride precipitated. The mixture was filtered through a celite pad, the solids were washed with ether, the filtrate was concentrated under reduced pressure. The residue was dissolved in methylene chloride and the organic layer was washed successively with aqueous sodium thiosulfate and water. The organic layer was dried over sodium sulfate, filtered and concentrated under reduced pressure to afford a foam. Flash chromatography on silica gel and elution with a graded mixture of hexane and ethyl acetate afforded methyl 6-O-(4-O-acetyl-2,3,6-tri-O-benzyl-α-D-galactopyranosyl) -2,3,4-tri-O-benzyl-α-D-glucopyranoside (2.314 g, 55%) as a foam.

Workup

  1. customsilver chloride precipitated
  2. filtrationThe mixture was filtered through a celite pad
  3. washthe solids were washed with ether
  4. concentrationthe filtrate was concentrated under reduced pressure
  5. dissolutionThe residue was dissolved in methylene chloride
  6. washthe organic layer was washed successively with aqueous sodium thiosulfate and water
  7. dry with materialThe organic layer was dried over sodium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated under reduced pressure
  10. customto afford a foam
  11. washFlash chromatography on silica gel and elution
  12. additionwith a graded mixture of hexane and ethyl acetate

Sources & evidence

ORD record
ord-19e4d15f31dc44b19404c446a981c5ad
Source dataset
uspto-grants-1992_03
Patent number
US05097023

Reaction notes

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