Methanol → methyl 2,3,5-tri-O-benzyl-L-xylofuranoside

HRID 638825Notes

Reaction equation

HRID 638825 reaction equation
[O:1]([CH3:11])[CH:2]1[O:8][C@@H:7]([CH2:9][OH:10])[C@@H:5]([OH:6])[C@@H:3]1O.[H-].[Na+].[CH2:14](Br)[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1.[CH3:22][OH:23]>O1CCCC1.[I-].C([N+](CCCC)(CCCC)CCCC)CCC>[CH2:22]([O:23][C@H:3]1[C@H:5]([O:6][CH2:14][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[C@H:7]([CH2:9][O:10][CH2:14][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[O:8][CH:2]1[O:1][CH3:11])[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1

Participants

7

Reactant 4

HCID 887MethanolHCID 7498Benzyl BromideHCID 24758Sodium hydrideHCID 12042993methyl L-xylofuranoside

Product 1

HCID 11015596methyl 2,3,5-tri-O-benzyl-L-xylofuranosideYield 87%

Reagents, catalysts & solvents 2

HCID 67553Tetrabutylammonium IodideCatalystHCID 8028TetrahydrofuranSolvent

Procedure

To an ice-cold solution of 2 (10 g, 60.9 mmol) in dry tetrahydrofuran (350 mL) was added sodium hydride (60% dispersion in mineral oil, 14.8 g, 370 mmol) and the reaction mixture was stirred for 15 min under N2. To this reaction mixture was added solid tetrabutylammonium iodide (0.36 g, 0.96 mmol) followed by a dropwise addition of benzyl bromide (36.6 g, 214 mmol). The reaction mixture was stirred for 3 days at room temperature. After the addition of methanol (25 mL) the solution was evaporated under reduced pressure, and the crude product was purified by silica gel chromatography (cyclohexane/EtOAc, 9: 1) to afford pure methyl 2,3,5-tri-O-benzyl-L-xylofuranoside (3, 23 g, 87% yield). MS 435 (M+H)+, 433 (M−H)+, 403 (M−OCH3)+; 1H NMR (CDCl3)δ 7.38-7.25 (m, 30H, aromatic H=s), 4.94 (d, 1H, H−1α, J1,2=4.3 Hz), 4.87 (d, 1H, H−1β, J,1,2 =0.9 Hz), 4.64-4.45 (m, 12H, PhCH2's), 4.37 (m, 1H, H−4α), 4.27 (dt, 1H, H−4β, J4,5a=3.7 Hz, J4,5b=6.5 Hz, J3,4=6.2 Hz), 4.17 (t, 1H, H-3α, J3,4=6.9 Hz, J2,3=5.6 Hz), 4.07 (dd, 1H, H-3β, J3,4=6.2 Hz, J2,3=2.5 Hz), 4.00 (dd, 1H, H-2α, J2,3=5.6 Hz), 3.95 (t, 1H, H-2β, J2,3=2.5 Hz), 3.70 (dd, 1H, H-5aα, J4,5a=4.5 Hz, J5a,5b=10.4 Hz), 3.66 (dd, 1H, H-5aβ, J4,5a=3.7 Hz, J5a,5b=10.7 Hz), 3.54 (dd, 1H, H-5bα, J4,5b=7.5 Hz), 3.49 (dd, 1H, H-5bβ, J4,5b=6.5 Hz).

Workup

  1. stirringThe reaction mixture was stirred for 3 days at room temperature
  2. customwas evaporated under reduced pressure
  3. customthe crude product was purified by silica gel chromatography (cyclohexane/EtOAc, 9: 1)

Sources & evidence

ORD record
ord-367625a709694bcfb124d79fc7c6d4d4
Source dataset
uspto-grants-2010_04
Patent number
US07691820B2

Reaction notes

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