Nanette M. Wachter*, Evan H. Kreth and Ronald P. D’Amelia,
{"title":"Calculating Thermodynamic Stabilities of Keto–Enol Tautomers of Aldehydes, Ketones, Esters, and Amides","authors":"Nanette M. Wachter*, Evan H. Kreth and Ronald P. D’Amelia, ","doi":"10.1021/acs.jchemed.4c00234","DOIUrl":null,"url":null,"abstract":"<p >Keto–enol tautomerization is paramount to understanding the mechanisms involved in many organic reactions and biochemical transformations. Isomerization of an enol to a carbonyl compound is typically introduced during the discussion of the acid-catalyzed electrophilic addition of water to alkynes. The tautomerization of carbonyl compounds to enol isomers is discussed in much greater detail when the reactions of carbonyl compounds are examined. This activity highlights the large differences in energies between the isomeric enol and carbonyl forms of simple aldehydes, ketones, esters, and amides. The computed energy values are used to calculate equilibrium constants for keto–enol tautomerization to further underscore the thermodynamic preference for the carbonyl forms. The results from student data support the thermodynamic enol produced by asymmetric ketones and reinforce the reactivity trends for aldehydes, ketones, esters, and amides.</p>","PeriodicalId":43,"journal":{"name":"Journal of Chemical Education","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Chemical Education","FirstCategoryId":"92","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acs.jchemed.4c00234","RegionNum":3,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Keto–enol tautomerization is paramount to understanding the mechanisms involved in many organic reactions and biochemical transformations. Isomerization of an enol to a carbonyl compound is typically introduced during the discussion of the acid-catalyzed electrophilic addition of water to alkynes. The tautomerization of carbonyl compounds to enol isomers is discussed in much greater detail when the reactions of carbonyl compounds are examined. This activity highlights the large differences in energies between the isomeric enol and carbonyl forms of simple aldehydes, ketones, esters, and amides. The computed energy values are used to calculate equilibrium constants for keto–enol tautomerization to further underscore the thermodynamic preference for the carbonyl forms. The results from student data support the thermodynamic enol produced by asymmetric ketones and reinforce the reactivity trends for aldehydes, ketones, esters, and amides.
期刊介绍:
The Journal of Chemical Education is the official journal of the Division of Chemical Education of the American Chemical Society, co-published with the American Chemical Society Publications Division. Launched in 1924, the Journal of Chemical Education is the world’s premier chemical education journal. The Journal publishes peer-reviewed articles and related information as a resource to those in the field of chemical education and to those institutions that serve them. JCE typically addresses chemical content, activities, laboratory experiments, instructional methods, and pedagogies. The Journal serves as a means of communication among people across the world who are interested in the teaching and learning of chemistry. This includes instructors of chemistry from middle school through graduate school, professional staff who support these teaching activities, as well as some scientists in commerce, industry, and government.