P-Cresol → 4-Methylphenyl 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranoside

HRID 863785Notes

Reaction equation

HRID 863785 reaction equation
[C:1]([O:4][CH:5]1[O:22][C@H:21]([CH2:23][O:24][C:25](=[O:27])[CH3:26])[C@H:16]([O:17][C:18](=[O:20])[CH3:19])[C@H:11]([O:12][C:13](=[O:15])[CH3:14])[C@H:6]1[O:7][C:8](=[O:10])[CH3:9])(=O)[CH3:2].[CH:28]1C(O)=C[CH:31]=[C:30]([CH3:35])[CH:29]=1>[Cl-].[Cl-].[Zn+2]>[C:8]([O:7][C@@H:6]1[C@@H:11]([O:12][C:13](=[O:15])[CH3:14])[C@@H:16]([O:17][C:18](=[O:20])[CH3:19])[C@@H:21]([CH2:23][O:24][C:25](=[O:27])[CH3:26])[O:22][C@@H:5]1[O:4][C:1]1[CH:28]=[CH:29][C:30]([CH3:35])=[CH:31][CH:2]=1)(=[O:10])[CH3:9]

Participants

4

Reactant 2

HCID 2879P-CresolHCID 2729838((2R,3S,4S,5R)-3,4,5,6-tetrakis(acetyloxy)oxan-2-yl)methyl acetate

Product 1

HCID 541416384-Methylphenyl 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosideYield 40%

Reagents, catalysts & solvents 1

HCID 3007855ZincchlorideCatalyst

Procedure

According to scheme XIV, the coupling of penta-O-acetyl-D-galactopyranose (36 g, 92 mmoles) with p-cresol (30 g, 280 mmoles) is carried out by fusion in the presence of anhydrous ZnCl2 (1.8 g) at 160° C. for 30 minutes, according Helferich technique. After cooling, a chromatography on a column of 60H silica (solvent:hexane-ethyl acetate: 90/10-v/v) is directly performed on the mixture and gives 15 g, yield=40% of 4-methylphenyl 2,3,4,6-tetra-O-acetyl-α-D-galactopyranoside, which crystallises in ethanol. Its analytical characteristics are identical as the one described before.

Workup

  1. temperatureAfter cooling

Sources & evidence

ORD record
ord-cf4cbe1b15964af294e3fcd1df036bad
Source dataset
uspto-grants-1996_10
Patent number
US05561119

Reaction notes

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