Production of a Derivative of 5 : 6 Anhydroglucose by the Hydrolysis of an Ethereal Sulphate

Abstract

ALTHOUGH it is now well established^1,2,3 that the alkaline hydrolysis of suitably substituted hexoses carrying sulphate groups on either the 3 or 6 positions readily yields 3 : 6 anhydrohexose derivatives, all our attempts to obtain evidence for the formation of ethylene oxide rings have been, until recently, unsuccessful, in marked contrast to the behaviour of the toluene-p-sulphonates⁴. It is now evident that this has been due largely to the fact that the barium salts of the sugar ethereal sulphates investigated were insoluble in organic solvents and the hydrolyses had, in consequence, to be carried out in aqueous media. Under such conditions experimental difficulties arise, for any ethylene oxide derivatives which may have been formed would be hydrolysed with accompanying Walden inversions⁴. Thus since the ethylene oxide ring formation would also involve a Walden inversion on the carbon atom where the sulphate group was originally attached, the production in recognizable quantity of a derivative of a hexose different from that in the original starting material depends on the relative ease of fission of the two ethylene oxide ring linkages. Thus the hydrolysis of a derivative of glucofuranose-3-sulphate could yield a 2 : 3 anhydro-allofuranose, which might give either a gluco- or an altrofuranose derivative, or both³.