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Peracylation de cyclodextrines (beta-CD et alfa-CD) par différents halogénures dיalkanoyle

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Peresterification of cyclodextrins (beta - and alfa-CD) by bromopropionyl bromide (BPB) or chloropropionyl chloride (CPC) was performed under mild reactions conditions. The various experimental parameters influencing the acylation have been defined Pyridine (PY) was used as catalyst and solvent in the presence of chloroform. The concentrations and the ratios X=[BPB}/[ beta-CD} and Y=[PY}/[BPB} have been varied. The mechanism and the reactivity of the reactive have been studied, and the obtained products were checked by 1H and 13C NMR, FAB-MS, FTIR, and elemental analysis. While BPB leads to a total esterification of the beta-CD and alfa-CD hydroxyl groups, esterification mediated by CPC is not quantitative and the kinetics are slower. The optimization ofthe CDs peresterification lead to new products. which were used as a macroinitiators for the atom transfer radical polymerization (ATRP) oftert-butylacrylate (t-BA) to prepare star shaped-polymers.

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