CHEMICAL MODIFICATION OF TREHALOSE .I. SELECTIVE SULPHONYLATION OF TREHALOSE AND DETERMINATION OF CONFORMATION OF HEXA-O-ACETYL-6,6'-DIDEOXYTREHALOSE

Selective esterification of α,α-trehalose with sulphonyl chlorides has been investigated. Selective dimethanesulphonylation of the disaccharide gave a mixture of the 6-ester and the 6,6′-diester, but in poor yield. Selective toluene-p-sulphonylation of trehalose gave the 6,6′-diester, readily isolable in 39% yield as the hexa-acetate, which is a useful starting material for the preparation of 6,6′-disubstituted derivatives of α,α-trehalose. The p.m.r. spectrum of hexa-O-acetyl-6,6′-dideoxy-α,α-trehalose, which may be prepared from the ditoluene-p-sulphonate, can be interpreted by first-order analysis and confirms that the D-glucopyranose units are physically equivalent and that they adopt the expected {A figure is presented} conformation. © 1968.