Unexpected regioselective debenzylation leading to modification of both rims of α-cyclodextrin

Diisobutylaluminum hydride-mediated debenzylation of perbenzylated alpha-cyclodextrin was investigated using modified conditions. It was found that the reaction proceeded much slower to allow a more controlled removal of benzyl groups. Prolonged reaction time led to the unprecedented observation that a cleavage of up to two benzyl groups can occur at the secondary rim in a highly regioselective manner. (C) 2009 Elsevier Ltd. All rights reserved.