2,3,4,6-Tetra-O-acetyl-alpha-D-galactopyranosyl bromide

White Crystalline Solid

Temperature and moisture sensitive; Store in freezer; Stabilized with 2% CaCO3

2,3,4,6-Tetra-O-acetyl-alpha-D-galactopyranosyl bromide can be synthesized by that: Methanolysis of the adduct prepared from the reaction of tetra‐O‐acetyl‐α‐d‐glucopyranosyl bromide with N,N‐dimethylthioformamide afforded the corresponding tetra‐O‐acetyl‐1‐thio‐d‐glucopyranose with an anomer ratio α/β of 52:48 in 98% yield.

Purify acetobromo-D-galactose as for the glucose analogue (next entry). If the compound melts lower than 87o or is highly coloured, then dissolve it in CHCl3 (ca 3 volumes) and extract with H2O (2 volumes), 5% aqueous NaHCO3, and again with H2O and dry it over Na2SO4. Filter and evaporate it in a vacuum. The partially crystalline solid or syrup is dissolved in dry Et2O (must be very dry) and recrystallised by adding pet ether (b 40-60o) to give a white product. [McKellan & Horecker Biochemical Preparations 11 111 1960, Beilstein 17/6 V 369.]

[1] TAKAYOSHI FUJIHIRA. Synthesis of Tetra-O-acetyl-1-thio-α-D-glucopyranose by Reaction of Tetra-O-acetyl-α-D-glucopyranosyl Bromide with N,N-Dimethylthioformamide.[J]. ChemInform, 2003, 34 33. DOI:10.1002/chin.200333198.