Sodium Methoxide → 1-deoxy-1-{4-[2-(trimethylsilyl)ethoxymethoxy]phenylthio}-beta-D-galactopyranose

HRID 1637440Notes

Reaction equation

HRID 1637440 reaction equation
[CH3:1][Si:2]([CH3:39])([CH3:38])[CH2:3][CH2:4][O:5][CH2:6][O:7][C:8]1[CH:13]=[CH:12][C:11]([S:14][C@@H:15]2[O:32][C@H:31]([CH2:33][O:34]C(=O)C)[C@H:26]([O:27]C(=O)C)[C@H:21]([O:22]C(=O)C)[C@H:16]2[O:17]C(=O)C)=[CH:10][CH:9]=1.C[O-].[Na+]>CO>[CH3:1][Si:2]([CH3:39])([CH3:38])[CH2:3][CH2:4][O:5][CH2:6][O:7][C:8]1[CH:13]=[CH:12][C:11]([S:14][C@@H:15]2[O:32][C@H:31]([CH2:33][OH:34])[C@H:26]([OH:27])[C@H:21]([OH:22])[C@H:16]2[OH:17])=[CH:10][CH:9]=1

Participants

4

Reactant 2

HCID 10942334Sodium MethoxideHCID 219675931-deoxy-1-{4-[2(trimethylsilyl)ethoxymethoxy]phenylthio}-2,3,4,6-tetra-O-acetyl-beta-D-galactopyranose

Product 1

HCID 702507151-deoxy-1-{4-[2-(trimethylsilyl)ethoxymethoxy]phenylthio}-beta-D-galactopyranose

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of the SEM protected thioglycoside 79 (1.60 g, 2.73 mmol) in 15 mL of methanol is added sodium methoxide (300 mg, 5.56 mmol). The mixture is stirred at room temperature for 12 h, then neutralized with Amberlite resin (acid form), filtered, concentrated and run through a short column of silica gel (10% MeOH/EtOAc) to provide crude 1-deoxy-1-{4-[2-(trimethylsilyl)ethoxymethoxy]phenylthio}-β-D-galactopyranose 80 as an oil: Rf 0.15 (EtOAc). The material is taken up in 10 mL of DMF, and dimethoxypropane (0.59 mL, 4.8 mmol), and p-toluenesulfonic acid hydrate (90 mg, 0.48 mmol) are added. The mixture is stirred at room temperature for 12 h, pyridine (0.04 mL, 0.48 mmol) is added, and the reaction mixture is concentrated and purified by flash chromatography (60% EtOAc/hexane) to give 0.5 g (41%) of 1-deoxy-3,4-O-isopropylidene-1-{4-[2-(trimethylsilyl)ethoxymethoxy]phenylthio}-β-D-galactopyranose 81 as a colorless oil: Rf 0.5 (67% EtOAc/hexane); 1H NMR (CDCl3, 300 MHz) δ 7.48 (d, J=8.6 Hz, 2H), 6.99 (d, J=8.6 Hz, 2H), 5.21 (s, 2H, SEM), 4.35 (d, J=10.2 Hz, 1H, H-1), 4.17 (dd, J=1.7, 5.4 Hz, 1H), 4.09 (dd, J=6.5 Hz, 1H), 3.94 (m, 1H), 3.85 (m, 2H), 3.73 (t, J=8.1 Hz, 2H, SEM), 3.52 (m, 1H), 2.49 (d, J=1.8 Hz, 1H), 2.17 (d, J=9.1 Hz, 1H), 1.40 (s, 3H, Me), 1.33 (s, 3H, Me), 0.93 (t, J=8.1 Hz, 2H, CH2 --TMS), 0.01 (s, 9H, SiMe3).

Workup

  1. filtrationfiltered
  2. concentrationconcentrated

Sources & evidence

ORD record
ord-c1e29692ffa0483584c882ae41d2742a
Source dataset
uspto-grants-2000_03
Patent number
US06040433

Reaction notes

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