DIBAL-H mediated triple and quadruple debenzylations of perbenzylated cyclodextrins.
Diisobutylaluminium hydride (DIBAL-H) mediated reductive removal of benzyl groups was investigated for perbenzylated alpha-, beta- and gamma-cyclodextrins using DIBAL-H in hexane as the reagent. It was found that under the new conditions, the debenzylation can be better controlled to provide sequentially tri- and tetra-debenzylated products in moderate yields and in a regioselective manner. In the case of alpha-cyclodextrin, the removal of the third and fourth benzyl groups took a different path involving the secondary rim, compared to beta- and gamma-cyclodextrins which both gave only 6-O-debenzylated products.
Rawal
Girish K
GK
Alberta Ingenuity Center for Carbohydrate Science, Department of Chemistry, University of Calgary, Calgary Alberta, T2N 1N4, Canada.
Rani
Shikha
S
Ward
Sandra
S
Ling
Chang-Chun
CC