Reaktion #68717

Reaktionsgleichung

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

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenwashed with 1N HCl (100 ml), water (100 ml) and brine (100 ml)
2. 2
   TrocknenThe organic phase was dried over sodium sulphate
3. 3
   Filtrationfiltered
4. 4
   Einengenconcentrated to dryness

Vorschrift

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.

Quelle