β‐Cycloaltrin: A Cyclooligosaccharide Consisting of Seven α(1 → 4)‐Linked Altropyranoses

Abstract

A surprisingly simple approach—heating per-2,3-anhydro-(2S)-β-cyclodextrin in water at reflux—provides the novel cyclooligosaccharide β-cycloaltrin (1) in 73% yield. In this one-step hydrolysis, ring opening results in the altro configuration in every sugar unit. The inclusion properties of 1 should be interesting.