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

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

Volume: 7 Issue: 2

Author(s): Ya-Xi Yang, Zheng Li, Guo-Rong Chen and Yuan-Chao Li

Affiliation:

Keywords: Mifepristone, estra-Δ5(10),9(11)-diene, cinchona alkaloids, chiral ammonium salts

Abstract: A modified phase-transfer catalysed enantioselective epoxidation of estra-Δ5(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 α/β epoxide up to 7:1.

Cite this article as:

Yang Ya-Xi, Li Zheng, Chen Guo-Rong and Li Yuan-Chao, Phase-Transfer Catalysed Enantioselective Epoxidation of Estra-Δ5(10),9(11)-diene Using Chiral Ammonium Salts Derived from Cinchona Alkaloids, Letters in Organic Chemistry 2010; 7 (2) . https://dx.doi.org/10.2174/157017810790796237