Synthesis of 6,1',6'-tri-O-(mesitylenesulfonyl)sucrose, further examination of "tri-O-tosylsucrose", and the chemistry of 3,6:1',4':3',6'-trianhydrosucrose.

Abstract Selective trimolar mesitylenesulfonylation of sucrose resulted in the formation of a highly crystalline trimesitylenesulfonate ( 1 ), which was isolated in greater than 50% yield without recourse to chromatography. As anticipated, the sulfonyl groups in 1 were located at the primary positions, as treatment with alkali afforded 3,6:1′,4′:3′,6′-trianhydrosucrose ( 4 ) in high yield. Fractionation of “tri- O -tosylsucrose” by high-pressure liquid chromatography effected separation of the minor isomer from the known, preponderant 6,1′,6′-isomer 3 . 13 C-N.m.r. spectroscopy indicated that the minor isomer was 2,6,6′-tri- O - p -tolylsulfonylsucrose ( 2 ). The trianhydride 4 was found to be dimorphous and was further characterized as the diacetate ( 5 ), the dibenzoate ( 6 ), the di- p -toluenesulfonate ( 7 ), and the dimethyl ether ( 8 ). Considerable differences in the reactivities toward acylation and etherification of the two axial hydroxyl groups in 4 permitted the preparation, in good yields, of the 4-acetate ( 9 ) and the 4 -methyl ether ( 12 ). Several derivatives of methyl 3,6-anhydro-α- d -glucopyranoside ( 13 ) were prepared for comparison with corresponding derivatives of 4 , and the hydroxyl groups in 13 also showed differences in reactivities analogous with those of 4 .