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2005
Hydroxycarboxylic acids (ether carboxylic acids) and esters
Q 0450
Chemoenzymatic Approach to Optically Active Phenylglycidates: Resolution of
and Iodohydrins. — With the aim to prepare enantiomerically enriched phe11- 098 Bromonylglycidates like (III), which are important intermediates in taxol and diltiazem preparation, the lipase-catalyzed hydrolysis of esters of type (I) is optimized. In a set of 22
hydrolases screened, only lipase AS (Aspergillus niger) is found to catalyze the hydrolysis with high enantioselectivity. The method fails to hydrolyze the corresponding propionates and butyrates. Toluene as co-solvent, and similarly MeCN, significantly
improves both the rate of hydrolysis and the enantioselectivity. Double kinetic resolution performed with partially enriched esters (I) further increases their enantioselectivites to 96—99%. The resolved alcohols and esters undergo facile conversion to the
desired glycidates in almost quantitative yields with no change in enantiopurity. —
(ANAND, N.; KAPOOR, M.; KOUL, S.; TANEJA*, S. C.; SHARMA, R. L.; QAZI,
G. N.; Tetrahedron: Asymmetry 15 (2004) 19, 3131-3138; Biotechnol. Div., Reg. Res.
Lab., Jammu Tawi 180 001, India; Eng.) — Klein
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