Реакция #68717

Уравнение реакции

BF3 Et2O

1,2,3,4-tetra-O-acetyl-β-D-glucopyranuronic acid methyl ester

2,2,2-trichloroethanol

→

1-O-trichloroethyl-2,3,4-tri-O-acetyl-α-D-glucopyranuronic acid methyl ester

Растворители

dichloromethane

Условия реакции

Обработка

1. 1
   Промывкаwashed with 1N HCl (100 ml), water (100 ml) and brine (100 ml)
2. 2
   СушкаThe organic phase was dried over sodium sulphate
3. 3
   Фильтрацияfiltered
4. 4
   Концентрированиеconcentrated to dryness

Методика

BF3-Et2O (15 ml) was added dropwise to a cooled solution at 0° C. of 1,2,3,4-tetra-O-acetyl-β-D-glucopyranuronic acid methyl ester (11.23 g, 0.03 mol) and 2,2,2-trichloroethanol (20 ml) in anhydrous dichloromethane (250 ml) under inert atmosphere. The mixture was stirred at room temperature overnight and then washed with 1N HCl (100 ml), water (100 ml) and brine (100 ml). The organic phase was dried over sodium sulphate, filtered and concentrated to dryness. 1-O-trichloroethyl-2,3,4-tri-O-acetyl-α-D-glucopyranuronic acid methyl ester 1 (8.95 g) was obtained after recrystallization of the crude product from ether.

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