Base-induced cyclization of .alpha.-chloro .beta.,.gamma.-unsaturated ketones : facile synthesis of tri- and tetrasubstituted 2-cyclopenten-1-ones
摘要:
Base-induced cyclization of fully substituted alpha-chloro beta,gamma-unsaturated ketones results in substituted cyclopentenones. Potassium tert-butoxide, lithium diisopropylamide, sodium hydroxide, and ammonium hydroxide can be used as the base for this process. In the case of ammonium hydroxide, it is proposed that initial formation of an enamine is followed by an intramolecular S(N)2' reaction of the enamine carbon. For all other bases, the reaction most likely proceeds through a ketone enolate. Application of this novel cyclization has been extended to the synthesis of several 2,3-disubstituted, 2,3,5-trisubstituted, and 2,3,5-tetrasubstituted 2-cyclopenten-1-ones.
Disclosed are compounds having the ability to inhibit cytochrome P450 2A6, 2A13, and/or 2B6 and tobacco products comprising them. Also disclosed are pharmaceutical compositions comprising them.
A SIMPLE SYNTHESIS OF DIHYDROJASMONE BY A NOVEL CYCLIZATION OF β,γ-ENONE
作者:Tamotsu Fujisawa、Kunikazu Sakai
DOI:10.1246/cl.1981.55
日期:1981.1.5
Dihydrojasmone was easily synthesized by bromination of 4-methyl-3-pentyl-4-penten-2-one, which was obtained by the alkylation of mesityl oxide, followed by the treatment with a base.
Organic Compounds and Compositions Having the Ability to Modulate Fragrance Compositions
申请人:Schilling Boris
公开号:US20100111888A1
公开(公告)日:2010-05-06
Disclosed are compounds having the ability to modulate, namely to improve, enhance and or modify fragrance compositions due to their ability to inhibit cytochrome P450 enzymes, e.g. CYP2A13 and CYP2B6.