Asymmetric epoxidation of α,β-unsaturated ketones under phase-transfer catalyzed conditions

Autor: Arai, Shigeru, Tsuge, Hiroki, Shioiri, Takayuki
Zdroj: Tetrahedron Letters; January 1998, Vol. 39 Issue: 41 p7563-7566, 4p
Abstrakt: Asymmetric epoxidation of a,b-unsaturated ketones with H 2O 2was developed using a chiral quaternary ammonium salt as the phase-transfer catalyst. A catalytic amount of N-[4-(iodo)benzyl]cinchoninium bromide, easily prepared from cinchonine, was effective in the asymmetric epoxidation for producing the corresponding desired products with up to 92% ee under mild reaction conditions.
Databáze: Supplemental Index