2,3,4,6-Tetrakis-O-(phenylmethyl)-D-galactopyranose → 2,3,4,6-Tetrakis-O-(phenylmethyl)-D-galactitol

HRID 1496821Notes

Reaction equation

HRID 1496821 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]1[OH:11])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[BH4-].[Na+]>C(O)C>[CH2:1]([O:8][C@H:9]([C@H:15]([C@H:14]([C@@H:13]([CH2:32][O:33][CH2:34][C:35]1[CH:36]=[CH:37][CH:38]=[CH:39][CH:40]=1)[OH:12])[O:24][CH2:25][C:26]1[CH:27]=[CH:28][CH:29]=[CH:30][CH:31]=1)[O:16][CH2:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1)[CH2:10][OH:11])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 27341542,3,4,6-Tetrakis-O-(phenylmethyl)-D-galactopyranoseHCID 4311764Sodium borohydride

Product 1

HCID 100075242,3,4,6-Tetrakis-O-(phenylmethyl)-D-galactitolYield 91%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

2,3,4,6-Tetra-O-benzyl-D-galactopyranose (107 g) was dissolved in ethanol (0.6 L) and, whilst stiffing at 0° C., sodium borohydride (31 g) was added. After stiffing overnight TLC analysis indicated completion of the reaction. The ethanol solution was partitioned between water (3 L) and ether (1.5 L). The organic phase was dried (Na2SO4), filtered and concentrated. The resulting oil was purified by flash chromatography (gradient elution using 20→50% ethyl acetate/petroleum ether) and then crystallised from a mixture of ethyl acetate/petroleum ether to give 2,3,4,6-tetra-O-benzyl-D-galactitol (97 g, 91%) as a white solid. 1H NMR (CDCl3): δ 2.4 (1H, bs), 3.35 (1H, bs), 3.55 (2H, m), 3.8 (3H, m), 3.9 (2H, m), 4.1 (1H, m), 4.4-4.8 (8H, m, OCH2Ph), 7.2-7.4 (20H, m, ArH). Mass spectrum: m/z 543 (M+H)+565 (M+Na)+.

Workup

  1. customwhilst stiffing at 0° C.
  2. customcompletion of the reaction
  3. customThe ethanol solution was partitioned between water (3 L) and ether (1.5 L)
  4. dry with materialThe organic phase was dried (Na2SO4)
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customThe resulting oil was purified by flash chromatography (gradient elution using 20→50% ethyl acetate/petroleum ether)
  8. customcrystallised from a mixture of ethyl acetate/petroleum ether

Sources & evidence

ORD record
ord-1d0e56e26a8c4f4a901849d8875b63cd
Source dataset
uspto-grants-2015_12
Patent number
US09199935B2

Reaction notes

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