Enzyme Promiscuity as a Remedy for the Common Problems with Knoevenagel Condensation
作者:Dominik Koszelewski、Ryszard Ostaszewski
DOI:10.1002/chem.201901491
日期:2019.8
lipase‐catalyzed tandemreaction toward α,β‐enones/enoesters is presented. For the synthesis of the desired products the tandem process based on enzyme‐catalyzed hydrolysis and Knoevenagel reaction starting from enol acetates and aldehyde is developed. The relevant impact of the reaction conditions including organic solvent, enzyme type, and temperature on the course of the reaction was revealed. It
The I.R. spectra of ethyl 4,4,4-trifluoroacetoacetate, ethyl 4,4-difluoroacetoacetate and ethyl 4-fluoroacetoacetate, their enol acetates and trifluoroacetates, and their copper chelates are compared with those of ethyl acetoacetate and its corresponding derivatives. The marked influence of neighboring fluorine atoms on the characteristics frequencies associated with such structures is noted. Related
Anodic perfluoroalkylation of the enol acetate of ethyl acetoacetate
作者:V. P. Kislyi、M. A. Kurykin、V. A. Grinberg、N. D. Kagramanov、V. V. Semenov
DOI:10.1007/bf01430645
日期:1996.12
Electrochemical perfluoroalkylation of the enol acetate of ethylacetoacetate was studied in the conditions of the Kolbe reaction. The yields of alkylation products depend on the competing adsorption of the enol acetate, the solvent, and perfluorocarboxylates on the surface of a platinum electrode.
The Claisen-Haase rearrangement of β-acyloxyacrylates, RC(O·COR′) : CH·CO2Et, into the isomeric diacylacetates, RCO·CH(COR′)·CO2Et, is subject to base and acid catalysis. The reaction is intermolecular when base-catalysed and probably intramolecular when acid-catalysed.
Über Cyclopentan-1,3-dione und isomere Enol-lactone. 5. Mitteilung
作者:Rob Richter
DOI:10.1002/hlca.19520350405
日期:1952.5.2
früher beschriebene “Substanz B” (Smp. 75–76°) wird durch ihren oxydativen Abbau mit KMnO4 zu Acetylglykolsäure und mit HNO3 zu Oxalsäure und Essigsäure als 5-Methyl-3-oxo-2,3-dihydrofuran-4-carbonsäure-äthylester (VI) aufgeklärt. Ferner werden die bei der katalytischen Hydrierung und der sauren und alkalischen Hydrolyse erhaltenen Produkte, sowie die UV.-Absorptionsspektren der “Substanz B” beschrieben