A General Mechanistic Scheme for Intramolecular Electrochemical Hydrocyclizations. Mechanism of the Electroreductive Cyclization of .omega.-Keto .alpha.,.beta.-unsaturated Esters
摘要:
A systematic procedure is suggested for formulating possible mechanisms by which electrochemical hydrocyclization and dehydrocyclization can occur. A combination of linear sweep voltammetry (LSV) and chemical and electrochemical arguments can be used to reduce the mechanistic possibilities to a small set or even a unique mechanism. The procedure is applied to the reductive cyclization of omega-keto-alpha,beta-unsaturated esters. Of the several hundred mechanistic possibilities for this process, the combination of LSV and chemical arguments can reduce the list to four; preparative-scale electrolysis of a specially designed substrate permits assignment of a unique mechanism, the e-P-d-c-p path, at low concentrations of electroactive substance.
highly efficient iridium-catalyzed asymmetric hydrogenation of racemic α-substituted lactones via dynamic kinetic resolution. Using Ir-SpiroPAP (R)-1d as a catalyst, a wide range of chiral diols were prepared in a high yield (80–95%) with a high enantioselectivity (up to 95% ee) under mild reaction conditions. This protocol was used for enantioselective syntheses of (−)-preclamol and a chiral 2,5-disubstituted
Polyhydroxyalkanoate having vinyl group, ester group, carboxyl group, and sulfonic group, and method of producing the same
申请人:Kenmoku Takashi
公开号:US20070073006A1
公开(公告)日:2007-03-29
To provide a novel polyhydroxyalkanoate having a reactive functional group in a molecule and a method of producing the same; and a novel polyhydroxyalkanoate having a new function obtained by chemically modifying the polyhydroxyalkanoate having a reactive functional group and a method of producing the same. By utilizing a vinyl group of a polyhydroxyalkanoate containing a unit having the vinyl group at a side chain thereof, a polyhydroxyalkanoate containing units having a carboxyl group, an amide group, and a sulfonic group in a molecule is induced.
Gemisch aus isomeren Alkylmethyltetrahydropyran-2-onen sowie ein Verfahren zu dessen Herstellung und Verwendung
申请人:HÜLS AKTIENGESELLSCHAFT
公开号:EP0401491A2
公开(公告)日:1990-12-12
2.1 Die Cyclopentanone der Formel (I)
fallen als Nebenprodukte an. Es bestand daher die Aufgabe, aus diesen Verbindungen hochwertige Feinchemikalien zu synthetisieren.
2.2 Es werden hierzu neue Isomerengemische aus 6-Alkyl-3-methyl- und 3-Alkyl-6-methyltetrahydropyran-2-onen vorgeschlagen, die durch Baeyer-Villiger-Oxidation synthetisierbar sind. Diese Produkte weisen einen charakteristischen Eigengeruch auf.
2.3 Verwendung der neuen Isomerengemische von Alkylmethyltetrahydropyranonen als Riechstoffe.