Direct regioselective 2-O-(p-toluenesulfonylation) of sucrose
摘要:
2-O-(p-Toluenesulfonyl)sucrose was regioselectively synthesized by direct p-toluenesulfonylation of sucrose using N-(p-toluenesulfonyl)imidazole in the presence of molecular sieves at 40degreesC. The reactivities of the sucrose hydroxy groups toward this sulfonylation increased in the order as follows: OH-2 much greater than OH-1' > OH-3' > OH-6 > OH-6'. These results were diametrically opposite to the expected sulfonylation with p-toluenesulfonyl chloride in pyridine. for which the reactivity increased in the order as follows: OH-6', OH-6 much greater than OH-1' > OH-2. The desired 2-O-(p-toluenesulfonyl)sucrose was readily isolated by simple open reversed-phase column chromatography. followed by recrystallization, thus overcoming the main difficulties associated with regioselectivity, efficiency, and isolation techniques for the practical preparation. (C) 2002 Elsevier Science Ltd. All rights reserved.
Direct regioselective 2-O-(p-toluenesulfonylation) of sucrose
作者:Katsunori Teranishi
DOI:10.1016/s0008-6215(02)00039-3
日期:2002.4
2-O-(p-Toluenesulfonyl)sucrose was regioselectively synthesized by direct p-toluenesulfonylation of sucrose using N-(p-toluenesulfonyl)imidazole in the presence of molecular sieves at 40degreesC. The reactivities of the sucrose hydroxy groups toward this sulfonylation increased in the order as follows: OH-2 much greater than OH-1' > OH-3' > OH-6 > OH-6'. These results were diametrically opposite to the expected sulfonylation with p-toluenesulfonyl chloride in pyridine. for which the reactivity increased in the order as follows: OH-6', OH-6 much greater than OH-1' > OH-2. The desired 2-O-(p-toluenesulfonyl)sucrose was readily isolated by simple open reversed-phase column chromatography. followed by recrystallization, thus overcoming the main difficulties associated with regioselectivity, efficiency, and isolation techniques for the practical preparation. (C) 2002 Elsevier Science Ltd. All rights reserved.