Sodium methoxide reaction with sugar sulfonates

Silver methanesulfonate, sulfonylation of carbohydrates by, 239 Sodium methoxide, reaction with sugar sulfonates, 279 Solubility... 

Internal-displacement reactions to give sugar anhydrides are well known, and anhydro derivatives of sucrose have been prepared by treatment of the respective sulfonates or chlorides with a base. Buchanan and coworkers described the synthesis of 3, 6 -anhydrosucrose by treating 2,3,4,6,l, 3, 4 -hepta-0-acetyI-6 -0-(p-ni-trophenylsulfonyl)sucrose with sodium ethoxide in ethanol for 2 h under reflux.18 Similar treatment of 2,3,4,l, 3, 4, 6 -hepta-0-acetyl-6-chloro-6-deoxysucrose (46) with sodium methoxide in methanol, followed by acetylation, gave crystalline 2,4,l, 3, 4, 6 -hexa-0-acetyl-3,6-anhydrosucrose (47) in 83% yield.81 The H n.m.r. spectrum of 47... 

The transformation of sulfonic esters into anhydro sugars has been reviewed extensively. Reaction of 2-0-sulfonyl derivatives of free sugars with sodium methoxide has since received attention initial formation of a 1,2-anhydro sugar is followed by production of a methyl glycoside of the C-2 epimeric sugar, in which the hydroxyl group on C-2 is trans to the methoxyl group on C-1. 

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