The prevalence of solvent effects in heterogeneous catalysis in condensed media has motivated developing quantitative kinetic, spectroscopic, and theoretical assessments of solvent structures and their interactions with reaction intermediates. Related Products of 97-65-4.
(+/-)-3-Butyryloxyquinuclidinium butyrate 6 (2 M, 571 g/L), prepared from (+/-)-quinuclidin-3-ol 1 and butyric anhydride, undergoes enantioselective hydrolysis by an Aspergillus melleus protease {1.0% (w/v)} in water in the presence of Ca(OH)(2) to keep the reaction at pH 7 and trap butyric acid that is introduced as part of (+/-)-6 and generated by the enzymatic hydrolysis. After a 24 h period, extraction with n-heptane provides (R)-quinuclidin-3-yl butyrate 5a, which, on methanolysis with Na2CO3, is converted into (R)-1, a common pharmacophore of neuromodulators acting on muscarinic receptors, in 96% ee and 42% overall yield from (+/-)-1. The unwanted antipode (S)-1, which is extracted into n-butanol and purified via its hydrochloride salt in 89% ee and 40% overall yield from (+/-)-1, can be racemized by the catalysis of Raney Co at 140degreesC under an atmosphere of H, (5 kg/cm(2)) to regenerate (+/-)-1 in 97% yield. (C) 2003 Elsevier Science Ltd. All rights reserved.
The design and synthesis of related molecules that are more effective, more selective, and less toxic than aspirin are important objectives of biomedical research.Keep reading other articles of 97-65-4. Related Products of 97-65-4.
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Quinuclidine – Wikipedia,
,Quinuclidine | C7H13N | ChemSpider