2-deoxy-P-D-glucoside

Aryl glycosides of 2-amino-2-deoxy sugars, as might be expected, can be prepared by similar techniques as was illustrated by the synthesis of phenyl 3,4,6-tri-0-acetyl-2-acetamido-2-deoxy-p-D-glucoside and -D-galactoside by toluene -sulphonic acid catalysed reactions between phenol and the hexosamine penta-acetates These products were then anomerised using zinc chloride as catalyst to provide means of obtaining -anomers. 

Acetamido-2-deoxy-P-D-glucoside acetamidodeoxyglucohydrolase 2-Acetamido-2-deoxy-P-D-hexoside acetamidodeoxyhexohydrolase see Cholinesterase... 

Sodium ascorbate and ascorbic acid esters, such as ascorbyl 6-palmitate (5-111) and ascorbyl 2-phosphate (5-113), are fully bioavailable, while ascorbyl 2-sulfate (5-114) is a completely inactive vitamin form. Phosphate and sulfate are about 20 times more stable to oxidation than the free acid. D-lsoascorbic acid (5-107) shows only 5-20% activity, 6-deoxy-L-ascorbic acid (5-115), found in fungi, has about 30% activity and the bound ascorbic acid form ascorbigen has 15-20% of the activity of ascorbic acid. Ascorbic acid 2-0-P-D-glucoside, systematic name 2-0-(P-D-glucopyranosyl)-L-ascorbic acid (5-116), has the same biological activity as ascorbic acid and is also stable against oxidation. 

Deoxy-sugars. Part X. Some Methanesulphonyl and Toluene-p-sulphonyl Derivatives of a-Ethyl-2 3-dideoxy-D-glucoside, S. Laland, W. G. Overend, and M. Stacey, /. Chem. Soc., (1950) 738-743. 

Deoxy-a-I mannopyranosyl)-7-(P-D-gluco- pyranosyloxy)-5-hydroxy-2-(4-hydroxyphenyl)4i7-l- benzopyran-4-one Isofurcatain-7-O-p-D-glucoside... 

The synthesis of 6-deoxy-D-glucose (see D-Quinovose, p, 99) is carried out from 2,3,4-tri-0-acetyl-6-bromo-6-deoxy-a-D-glucosyl bromide. The dihalide is converted to the methyl 2,3,4-tri-0-acetyl-6-bromo-6-deoxy-i -D-glucoside by treatment with silver carbonate and methyl alcohol, and the bromine is exchanged for a hydrogen atom by reduction with zinc and acetic acid 227). 

In 1977 Tatsuta et al. [22] reported that 3,4,6-tri-O-acetyl-D-glucal 10 reacted with various alcohols in the presence of A -bromosuccmimide in acetonitrile to give mainly the 2-bromo-2-deoxy-a-D-mannopyranosides in 70-90% yields. With the exception of methanol, the a-mannof -gluco ratio was estimated to be better than 95 5 when the reaction was performed at 5 °C higher temperatures increased the amount of P-glucosides. As for protonation, this procedure is limited to sugar primary alcohols such as 32 leading to an a-(1 6) disaccharide 33 in excellent yield (Scheme 7). 

Phytosterols and their glucosides are common constituents of ferns. Acylated glucosides such as 820 (392) also occur in all ferns. From Pteris inaequalis var. aequata which contains 2-deoxy-D-glucose (835) abundantly, 2-deoxy-D-glucoside of P-sitosterol (821) has been isolated together with its P-D-glucoside (289). 

---