An efficient synthetic-route to prepare [2,3,6-tri-O-(2-bromo-2-methylpropionyl]-β-cyclodextrin)

The efficient approach for the synthesis of [2,3,6-tri-O-(2-bromo-2-methylpropionyl]-beta-cyclodextrin) (21Br-beta-CD) is described. The reaction between 2-bromoisobutyric bromide and P-cyclodextrin was performed directly in 1-methyl-2-pyrrolidione solvent, leading to much less complicated procedures and higher yield (up to 89.5%) compared with those reported previously (17% yield). The product is an extremely useful initiator in synthesizing star polymers with well-defined structures using atom transfer radical polymerization for biomedical applications. (c) 2005 Elsevier Ltd. All rights reserved.