Regiospecific Tandem Azide‐Reduction/Deprotection To Afford Versatile Amino Alcohol‐Functionalized α‐ and β‐Cyclodextrins

Cyclic conundrum: Deciphering the cyclic directionality of cyclodextrins allows the precise regiospecific synthesis of functionalized cyclodextrins with diametrically opposed amino and hydroxy groups (see scheme; DIBAL-H=diisobutylaluminum hydride, Bn=benzyl) through a tandem azide-reduction/debenzylation mechanism. A remarkable feature of this process is the long-distance discrimination between two equidistant benzyl groups on β-cyclodextrin.