Phase-Transfer Catalysed Enantioselective Epoxidation of Estra-Δ5(10),9(11)-diene Using Chiral Ammonium Salts Derived from Cinchona Alkaloids

Authors :: Yaxi Yang
Guo-Rong Chen
Zheng Li
Yuanchao Li
Source :: Letters in Organic Chemistry. 7:163-167
Publication Year :: 2010
Publisher :: Bentham Science Publishers Ltd., 2010.
Abstract: A modified phase-transfer catalysed enantioselective epoxidation of estra-Delta(5(10),9(11))-diene, an important intermediate of anti-early pregnancy drug mifepristone 1, have been determined and investigated. Eight chiral ammonium salts (PTC A-H), used as phase-transfer catalysts, have been synthesized from cinchona alkaloids. Among them, PTC G and PTC H have exhibited satisfying catalytic activity to improve the ratio of alpha/beta epoxide up to 7:1.

Subjects :: chemistry.chemical_compound
chemistry
Diene
Phase (matter)
Organic Chemistry
Enantioselective synthesis
Epoxide
Organic chemistry
Ammonium
Cinchona Alkaloids
Biochemistry
Catalysis

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