beta-Cycloaltrin: A Cyclooligosaccharide Consisting of Seven alpha(l -> 4)-Linked Altropyranoses

摘要

Cyciodextrins. for example beta-cvclodextrin (1) (Scheme 1). are cyclic oligosacchandes made up of 1.4-linked D-glucopyranose units in ~4C_1, chair conformation. They can include a wide variety of substrates in their hydrophobia cavities. The formation of inclusion complexes and reactions constrained to the cavities have been studied extensively. Several cvcioolisosacchandes uniformly composed of sugars other than glucose have been reported such as the inulin-derived 7-cyclofructin.alpha- and beta-cycloinannms. synthesized chemically. and x-cyclogaluctm. which so far has been characterized by molecular modeling only. In this paper, we report the preparation of a novel cyclooligosacchande constituted of seven alpha(1 ->4)-linked al-tropyranoses, which we designate, in accord with a recent proposal for simplified nomenclature, as beta-cycloaltrin (3) (Scheme 1).