Rogmann N, Seidel J, Mischnick P
Universität Hamburg, Institut für Organische Chemie, Germany.
Carbohydr Res. 2000 Jul 24;327(3):269-74. doi: 10.1016/s0008-6215(00)00057-4.
The distribution of substituents in sulfonylbutylethers of cyclomaltoheptaose (beta-cyclodextrin) formed in aqueous medium has been determined by gas chromatography after hydrolysis and formation of the permethylated sulfonylfluoride derivatives. In contrast to other etherification reactions of beta-cyclodextrin, preferred substitution in position 3 of the glucose units has been detected. From 1H NMR and microcalorimetric experiments, the formation of host-guest complexes by beta-cyclodextrin and the reagent 1,4-butane sultone in water became evident. This spatial preorganization presumably favors the reaction with the O-3. In contrast, in methyl sulfoxide preferred 2-O-alkylation was obtained, indicating that host-guest interaction does not influence regioselectivity in this solvent.
在水解并形成全甲基化磺酰氟衍生物后，通过气相色谱法测定了在水性介质中形成的环麦芽七糖（β-环糊精）的磺酰丁基醚中取代基的分布。与β-环糊精的其他醚化反应不同，已检测到葡萄糖单元的3位存在优先取代。通过1H NMR和微量量热实验表明，β-环糊精与试剂1,4-丁烷磺内酯在水中形成了主客体复合物。这种空间预组织可能有利于与O-3的反应。相比之下，在二甲基亚砜中获得了优先的2-O-烷基化，这表明主客体相互作用不会影响该溶剂中的区域选择性。
