Benzyl Bromide → methyl 2,3,4,6-tetra-O-benzyl-alpha-D-glucopyranoside

HRID 1488289Notes

Reaction equation

HRID 1488289 reaction equation
[H-].[Na+].[CH3:3][O:4][C@H:5]1[O:10][C@H:9]([CH2:11][OH:12])[C@@H:8]([OH:13])[C@H:7]([OH:14])[C@H:6]1[OH:15].[CH2:16](Br)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1>CN(C=O)C.[Br-].C([N+](CCCC)(CCCC)CCCC)CCC>[CH2:16]([O:15][C@@H:6]1[C@@H:7]([O:14][CH2:16][C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[C@H:8]([O:13][CH2:16][C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[C@@H:9]([CH2:11][O:12][CH2:16][C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[O:10][C@@H:5]1[O:4][CH3:3])[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1

Participants

6

Reactant 3

HCID 7498Benzyl BromideHCID 24758Sodium hydrideHCID 64947methyl alpha-D-glucopyranoside

Product 1

HCID 10840491methyl 2,3,4,6-tetra-O-benzyl-alpha-D-glucopyranoside

Reagents, catalysts & solvents 2

HCID 74236Tetrabutylammonium BromideCatalystHCID 6228DimethylformamideSolvent

Procedure

To a suspension of NaH (5.19 g of a 60% dispersion in oil, 130 mmol) in DMF (150 mL) was added portionwise methyl-α-D-glucopyranoside (4.2 g, 21.6 mmol). The resulting mixture was stirred at rt for 2 hr, to which tetrabutyl ammonium bromide (800 mg, 2.16 mmol) was and followed by dropwise addition of benzyl bromide (11.58 mL, 97 mmol). After stirring at rt overnight, the mixture was concentrated and the residue was suspended in water and extracted with ether (3×150 mL). The combined ether layers were washed with brine (200 mL), dried over Na2SO4, filtered and evaporated. The residue was purified by flash chromatography on silica gel (330 g), eluting with 0-30% EtOAc in hexanes to give the title compound. 1H NMR (CDCl3, 400 MHz) δ 3.44 (s, 3H), 3.62 (dd, J=9.6, 3.5, 1H), 3.66-3.72 (m, 2H), 3.75-3.82 (m, 2H), 4.04 (t, J=9.3, 1H), 4.51-4.55 (m, 2H), 4.66 (d, J=12.1, 1H), 4.69 (d, J=3.5, 1H), 4.72 (d, J=12.1, 1H), 4.83-4.90 (m, 3H), 5.04 (d, J=11.0, 1H), 7.19 (m, 2H), 7.30-7.43 (m, 18H).

Workup

  1. concentrationthe mixture was concentrated
  2. extractionextracted with ether (3×150 mL)
  3. washThe combined ether layers were washed with brine (200 mL)
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. customevaporated
  7. customThe residue was purified by flash chromatography on silica gel (330 g)
  8. washeluting with 0-30% EtOAc in hexanes

Sources & evidence

ORD record
ord-50a2b371037e4f45bec874266911cffb
Source dataset
uspto-grants-2016_08
Patent number
US09427475B2

Reaction notes

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