Dimethylformamide → (2R,3R,4S,5R,6R)-3,4,5-Tris(benzyloxy)-2-bromo-6-(3-phenylpropyl)tetrahydro-2H-pyran

HRID 475663

Reaction equation

HRID 475663 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]([CH2:32][O:33][CH2:34][C:35]2[CH:40]=[CH:39][CH:38]=[CH:37][CH:36]=2)[O:12][CH:10]1O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.CN(C=O)C.C(Br)(=O)C([Br:49])=O.C(OCC)(=O)C>C(Cl)Cl>[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]([CH2:32][O:33][CH2:34][C:35]2[CH:40]=[CH:39][CH:38]=[CH:37][CH:36]=2)[O:12][C@@H:10]1[Br:49])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 8857Ethyl AcetateHCID 84841Ethanedioyl dibromideHCID 109405022,3,4,6-Tetrakis-O-(phenylmethyl)-D-glucopyranose

Product 1

HCID 11061062(2R,3R,4S,5R,6R)-3,4,5-Tris(benzyloxy)-2-bromo-6-(3-phenylpropyl)tetrahydro-2H-pyranYield 95.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

2,3,4,6-Tetra-O-benzyl-D-glucopyranose (1.0 g, 1.9 mmol) was dissolved in anhydrous DCM (6 mL) and anhydrous DMF (0.4 mL) under argon. The resulting solution was stirred at 0° C. Oxalyl bromide (4 mL, 2M in DCM, 24 mmol) was added dropwise over a 5 min period . The reaction was stirred at RT. After a 40 min period, t.l.c. (petrol:ethyl acetate, 2:1) indicated the formation of a major product (Rf 0.7). The reaction was cooled to 0° C. and quenched with ice cold water (30 mL) added over a 5 min period. The reaction was partitioned between DCM (20 mL) and water. The aqueous layer was re-extracted with DCM (3×20 mL), the combined organic layers were washed with brine (40 mL), dried (MgSO4), filtered and concentrated in vacuo to afford the title product (1.10 g, 95%) as a crude yellow oil; δH (400 MHz, CDCl3), 3.57 (1H, dd, J1,2 3.5 Hz, J2,3 9.1 Hz, H-2), 3.68 (1H, dd, J5,6 2.1 Hz, J6,6′ 11.0 Hz, H-6), 3.79-3.84 (2H, m, H-4, H-6′), 4.07 (1H, at, J9.1 Hz, H-3), 4.07-4.11 (1H, m, H-5), 4.47-4.62 (3H, m, PhCH2), 4.74 (s, 2H, PhCH2), 4.84-4.89 (2H, m, PhCH2), 5.10 (1H, d, J11.1 Hz, PhCH2), 6.46 (1H, d, H-1), 7.15-7.41 (20H, m, Ar—H).

Workup

  1. stirringThe reaction was stirred at RT
  2. temperatureThe reaction was cooled to 0° C.
  3. customquenched with ice cold water (30 mL)
  4. additionadded over a 5 min period
  5. customThe reaction was partitioned between DCM (20 mL) and water
  6. extractionThe aqueous layer was re-extracted with DCM (3×20 mL)
  7. washthe combined organic layers were washed with brine (40 mL)
  8. dry with materialdried (MgSO4)
  9. filtrationfiltered
  10. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-eb6bc162a6a844d8b2816feb171834c9
Source dataset
uspto-grants-2014_01
Patent number
US08637578B2

Linked notes

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