The keto–enol tautomerization of ethyl butylryl acetate studied by LC-NMR

✍ Scribed by Casey Chun Zhou; David R. Hill

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 252 KB
• Volume: 45
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1930

✦ Synopsis

Abstract

The keto–enol tautomerism of ethyl butylryl acetate was studied in mixed solvents under a variety of experimental conditions. The direct measurement of ketonization of the enol tautomer was performed by using the hyphenated technique LC‐NMR. The keto and enol tautomers can be separated by using HPLC and their interconversion is a slow process on the NMR timescale. The ketonization reaction was found to be acid catalyzed and the solvent isotope effect, k/k, in an acetonitrile/water mixture, is 5.4. The ketonization rate constants were also measured at different compositions of binary solvents, such as CH~3~CN/D~2~O, CD~3~OD/D~2~O, and CH~3~CN/CD~3~OD. The rate constant and water percentage were found to have an exponential relationship. The reaction rate as a function of solvent polarity will be discussed in this paper. Copyright © 2006 John Wiley & Sons, Ltd.