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

反応式

[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]

参加物

反応物 2

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

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

生成物 2

HCID 887Methanol収率 76%

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

実験手順

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%).