Selective Halogenation at Primary Positions of Cyclomaltooligosaccharides and a Synthesis of Per‐3,6‐anhydro Cyclomaltooligosaccharides

The cyclodextrin derivatives 2, which contain glucopyranose units in 1C4 conformation, were obtained via the 6-iodo compounds 1. The synthesis of 1 was accomplished by reaction of unsubstituted sugars with Vilsmeier-type reagents (see also following communication).