1,3-Dibromo-5,5-dimethylhydantoin → 4-Bromomethylphenyl 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranoside

Reaction equation

[C:1]([O:4][C@@H:5]1[C@@H:18]([O:19][C:20](=[O:22])[CH3:21])[C@@H:17]([O:23][C:24](=[O:26])[CH3:25])[C@@H:16]([CH2:27][O:28][C:29](=[O:31])[CH3:30])[O:15][C@@H:6]1[O:7][C:8]1[CH:13]=[CH:12][C:11]([CH3:14])=[CH:10][CH:9]=1)(=[O:3])[CH3:2].[Br:32]N1C(C)(C)C(=O)N(Br)[C:34]1=[O:35]>>[C:1]([O:4][C@@H:5]1[C@@H:18]([O:19][C:20](=[O:22])[CH3:21])[C@@H:17]([O:23][C:24](=[O:26])[CH3:25])[C@@H:16]([CH2:27][O:28][C:29](=[O:31])[CH3:30])[O:15][C@@H:6]1[O:7][C:8]1[CH:9]=[CH:10][C:11]([CH2:14][Br:32])=[CH:12][CH:13]=1)(=[O:3])[CH3:2].[CH3:34][OH:35]

Participants

Reactant 2

HCID 64791,3-Dibromo-5,5-dimethylhydantoin

HCID 541416384-Methylphenyl 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranoside

Product 2

HCID 887MethanolYield 76%

HCID 539280404-Bromomethylphenyl 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosideYield 422.9%

Procedure

1.4 g (3.2 mmoles) of 4-methylphenyl 2,3,4,6-tetra-O-acetyl-α-D-galactopyranoside (71) and 0.46 g (1.6 mmole) of 1,3-dibromo 5,5-dimethylhydantoine are added in 100 ml of carbone tetrachloride, and the mixture est refluxed under irradiation with light (1 000 W) for 15 minutes. After cooling, the reaction medium is filtered and the filtrate is then evaporated to dryness. 3.5 g of 4-bromomethylphenyl 2,3,4,6-tetra-O-acetyl-α-D-galactopyranoside (72) are isolated by crystallization from methanol (yield=76%).