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Regioselective silylation of C-2 hydroxyl group of α-cyclodextrin dependent on reaction temperature

✍ Scribed by Katsunori Teranishi; Fumiko Ueno

Publisher: Elsevier Science
Year: 2002
Tongue: French
Weight: 96 KB
Volume: 43
Category: Article
ISSN: 0040-4039
DOI: 10.1016/s0040-4039(02)00258-7

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✦ Synopsis

Silylations of the C-2 hydroxyl group of a-cyclodextrin were carried out using t-butyldimethylsilyl imidazole in the presence of 4 A , molecular sieves in N,N-dimethylformamide. A unique aspect of this silylation method is the temperature dependence of the regioselectivity; silylation at 0°C regioselectively favored the C-6 position to afford mono-6-O-tbutyldimethylsilyl-a-cyclodextrin, whereas silylation at 140°C exhibited high regioselectivity on the C-2 hydroxyl group.

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