Tetra-O-acetyl-a-D-glucopyranosyl chloride

Ci4H1gC109 Tetra-O-acetyl-a-D-glucopyranosyl chloride ACGLUP 31 368... 

Tetra-O-acetyl-a-D-glucopyranosyl Chloride, R. U. Lemieux, Methods Carbohydr. Chem., 2 (1963) 223-224. 

In 1945, Hurd and Bonner129 130 reported the reaction of either tetra-O-acetyl-a-D-glucopyranosyl chloride or penta-0-acetyl-/3-D-glucopy-ranose with benzene in the presence of aluminum chloride, to form 1,2-/rans-/3-D-glucopyranosylbenzene. The implication of the above results (on /3-D-glucoside formation) in connection with the nature of this latter reaction is obvious. 

In a study of the reaction of the anomeric forms of penta-O-acetyl-D-glucopyranose with titanium chloride in chloroform solution, Lemieux and Brice have found that, at 40°, the a-D anomer reacts but slowly, whereas the /3-d anomer reacts extremely rapidly, with the initial formation of (unstable) tetra-0-acetyl- S-D-glucopyranosyl chloride which then rearranges relatively slowly to (stable) tetra-O-acetyl-a-D-glucopyranosyl chloride. 

In 1879, Michael14 reported that phenyl /3-D-glucopyranoside (3) is obtained by the reaction of tetra-O-acetyl-a-D-glucopyranosyl chloride (1) with potassium phenoxide in aqueous solution. Under the reaction... 

In the first successful synthesis of a 1,2-trans glycoside, 2,3,4,6-tetra-O-acetyl-a-D-glucopyranosyl chloride was treated with the potassium salt of a phenol. Under the conditions used, deacylation occurred. 

The first successful synthesis of glycosides was carried out by Michael. The synthesis was accomplished by the interaction of tetra-O-acetyl-a-D-glucopyranosyl chloride (I) and the potassium salts of phenols (I). Under the conditions of the reaction, acetyl groups were also removed, and the glycoside was produced. 

Fluorination with Silver Fluoride from Glycosyl Bromide [17] A mixture of 2,3,4,6-tetra- O-acetyl-a-D-glucopyranosyl bromide (5 g) and anhydrous silver fluoride (5 g) in dry acetonitrile (25 ml) was shaken under argon overnight. The resulting solution was filtered and aqueous sodium chloride was added to precipitate any silver ions from the solution. The mixture was filtered and concentrated to a syrup that was... 

Cinnolin-3(2/f)-one (7) is methylated with diazomethane or methyl sulfate to give 2-methylcinnolin-3(2/f)-one. In a similar manner, benzylation with benzyl chloride, cyanoethylation with acrylonitrile in the presence of benzyltrimethylammonium hydroxide and glucosidation with tetra-O-acetyl-a-D-glucopyranosyl bromide in the presence of a base affords the corresponding 2-substituted cinnolin-3(2Hr)-ones. However, glucosidation of the silver salt of cinnolin-3(2/f)-one produces the corresponding O-substituted compound. 

Baker 19 has cited the conversion of tetra-O-acetyl-a-D-glucopyranosyl bromide (a cis halogeno sugar) to the less stable beta (trans) isomer with silver chloride [H. H. Schlubach, Ber., 69, 840 (1926)] as an example of this reaction. Lemieux (see Ref. 224) suggested that, in this anomerization, the mechanism is of the SnI rather than the Ss2 type (proceeding by way of an orthoester ion). 

Silyl derivatives of purines are commonly used in the same way as in a synthesis of 9-(a, -D-glucopyranosyl)adenine from AT -benzoyl-9-bis(trimethylsilyl)adenine and 2,3,4,6-tetra-O-acetyl-a-D-glucosyl chloride at 150-160 °C over 4 hours to produce, after deblocking, a mixture of anomeric nucleosides (B-68MI40901,p. 135). The hypoxanthine nucleosides may be obtained in a similar fashion or by deamination of the adenine derivatives. 

---