Benzyl Bromide → 1-allyl-1-deoxy-2,3,4-tri-O-benzyl-alpha-L-fucopyranose

HRID 1488285Notes

Reaction equation

HRID 1488285 reaction equation
[H-].[Na+].[C@@H:3]1([CH2:13][CH:14]=[CH2:15])[O:11][C@@H:10]([CH3:12])[C@@H:8]([OH:9])[C@@H:6]([OH:7])[C@@H:4]1[OH:5].[CH2:16](Br)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1>CN(C=O)C.[I-].C([N+](CCCC)(CCCC)CCCC)CCC>[CH2:16]([O:5][C@H:4]1[C@H:6]([O:7][CH2:16][C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[C@H:8]([O:9][CH2:16][C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[C@H:10]([CH3:12])[O:11][C@H:3]1[CH2:13][CH:14]=[CH2:15])[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1

Participants

6

Reactant 3

HCID 7498Benzyl BromideHCID 24758Sodium hydrideHCID 110741613-(alpha-L-fucopyranosyl)-1-propene

Product 1

HCID 153448101-allyl-1-deoxy-2,3,4-tri-O-benzyl-alpha-L-fucopyranose

Reagents, catalysts & solvents 2

HCID 67553Tetrabutylammonium IodideCatalystHCID 6228DimethylformamideSolvent

Procedure

To a stirred suspension of NaH (3.91 g, 60% dispersion in oil, 98 mmol) in DMF (120 mL) at rt was added portionwise 3-(α-L-fucopyranosyl)-1-propene (4.6 g, 24.44 mmol). After 2 hr, to the resulting mixture was added tetrabutyl ammonium iodide (451 mg, 1.22 mmol) and followed by the slow addition of benzyl bromide (13.1 mL, 110 mml) After stirring at rt for 16 hr, the reaction mixture was concentrated and the residue was partitioned between water (300 mL) and Et2O (150 mL). The aqueous layer was extracted with Et2O (3×150 mL). The combined organic layers were washed with brine (100 mL), dried over Na2SO4, filtered and concentrated. The residue was purified by flash chromatography on silica gel (220 g), eluting with 0-40% EtOAc in hexanes to give the title compound. 1H NMR (CDCl3, 400 MHz) δ 1.34 (d, J=6.6, 3H), 2.33 (m, 1H), 2.42 (m, 1H), 3.82 (m, 3H), 3.99 (m, 1H), 4.12 (m, 1H), 4.58 (d, J=11.8, 1H), 4.64 (d, J=11.8, 2H), 4.69 (d, J=12.0, 1H), 4.76 (dd, J=12.0, 8.9, 2H), 5.05, 5.07 and 5.11 (m, 2H), 5.80 (m, 1H), 7.30-7.40 (m, 15H).

Workup

  1. concentrationthe reaction mixture was concentrated
  2. customthe residue was partitioned between water (300 mL) and Et2O (150 mL)
  3. extractionThe aqueous layer was extracted with Et2O (3×150 mL)
  4. washThe combined organic layers were washed with brine (100 mL)
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe residue was purified by flash chromatography on silica gel (220 g)
  9. washeluting with 0-40% EtOAc in hexanes

Sources & evidence

ORD record
ord-9e56db25ab7b460eb25378317e930bfc
Source dataset
uspto-grants-2016_08
Patent number
US09427475B2

Reaction notes

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