Phosphate esters of sugars

Mannitol hexanitrate is obtained by nitration of mannitol with mixed nitric and sulfuric acids. Similarly, nitration of sorbitol using mixed acid produces the hexanitrate when the reaction is conducted at 0—3°C and at —10 to —75°C, the main product is sorbitol pentanitrate (117). Xylitol, ribitol, and L-arabinitol are converted to the pentanitrates by fuming nitric acid and acetic anhydride (118). Phosphate esters of sugar alcohols are obtained by the action of phosphorus oxychloride (119) and by alcoholysis of organic phosphates (120). The 1,6-dibenzene sulfonate of D-mannitol is obtained by the action of benzene sulfonyl chloride in pyridine at 0°C (121). To obtain 1,6-dimethanesulfonyl-D-mannitol free from anhydrides and other by-products, after similar sulfonation with methane sulfonyl chloride and pyridine the remaining hydroxyl groups are acetylated with acetic anhydride and the insoluble acetyl derivative is separated, followed by deacetylation with hydrogen chloride in methanol (122). Alkyl sulfate esters of polyhydric alcohols result from the action of sulfur trioxide—trialkyl phosphates as in the reaction of sorbitol at 34—40°C with sulfur trioxide—triethyl phosphate to form sorbitol hexa(ethylsulfate) (123). 

Examples of the synthesis of phosphite and phosphate esters of sugars are included in a review on trivalent phosphorous acids (Scheme 5). The synthesis of an oxyphosphorane has also been reported (Scheme 6). A strategy for regioselective phosphorylation of aldoses in aqueous solution involves reversible attachment of activated diamidophosphate (DAP). The carbonyl addition prod-... 

The use of phosphorus oxychloride for the synthesis of phosphate esters of sugars 160) has been largely replaced by dibenzyl 161) and diphenyl phosphorochloridates 162), The latter reagent may be prepared in a pure, stable form which reacts readily with an alcohol in pyridine at low temperature. The phenyl groups may be removed from the resulting di-0-phenyl phosphate derivative of the alcohol by catalytic hydrogenation employing a platinum catalyst. 

Cytokinins promote cell division in plant tissues. They are aminopurines and as such as linlced to phosphate esters of sugars to form nucleosides and nucleotides,... 

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