Editing Lactone (section)

==Etymology==
The name ''lactone'' derives from the ring compound called [[lactide]], which is formed from the dehydration of 2-hydroxypropanoic acid ([[lactic acid]]) CH<sub>3</sub>-CH(OH)-COOH. Lactic acid, in turn, derives its name from its original isolation from soured milk (Latin: lac, lactis). The name was coined in 1844 by the French chemist [[Théophile-Jules Pelouze]], who first obtained it as a derivative of lactic acid.<ref>{{cite journal |last1=Pelouze |first1=J. |title=Mémoire sur l'acide lactique |journal=Comptes rendus |date=9 December 1844 |volume=19 |pages=1219–1227 |url=https://www.biodiversitylibrary.org/item/81358#page/1237/mode/1up |trans-title=Memoir on lactic acid |language=fr}}
From p. 1223:  ''"Indépendamment de la lactide dont je viens de rappeler l'existence dans les produits de la distllation de l'acide lactique, celui-ci donne encore, par sa décomposition, une autre substance, que je propose d'appeler ''lactone'', parce qu'elle me paraît être à l'acide lactique ce que l'acétone est à l'acide acétique."''  (Independently of the lactide of which I have just recalled the existence in the products of the distillation of lactic acid, this [i.e., lactic acid] gives further, by its decomposition, another substance, which I propose to call ''lactone'', because it seems to me to be to lactic acid what acetone is to acetic acid.)
*  Reprinted:  {{cite journal |last1=Pelouze |first1=J. |title=Mémoire sur l'acide lactique |journal=Annales de Chimie et de Physique |date=1845 |volume=13 |pages=257–268 |url=https://babel.hathitrust.org/cgi/pt?id=hvd.hx3dxr&view=1up&seq=276&q1=262 |series=3rd series |trans-title=Memoir on lactic acid |language=fr}} ; see p. 262.
*  English translation:  {{cite journal |last1=Pelouze |first1=J. |title=Researches on lactic acid |journal=The Chemical Gazette |date=January 15, 1845 |volume=3 |issue=54 |pages=29–35 |url=https://books.google.com/books?id=1BkFAAAAQAAJ&pg=PA29}} ; see p. 31.
*  {{cite book |last1=Menten |first1=Pierre de |title=Dictionnaire de chimie: Une approche étymologique et historique |trans-title=Dictionary of Chemistry: an etymological and historical approach |date=2013 |publisher=de boeck |location=Brussels, Belgium |page=183 |isbn=9782804181758 |url=https://books.google.com/books?id=NKTKDgAAQBAJ&pg=PA183 |language=fr}}</ref> An internal [[dehydration reaction]] within the same molecule of lactic acid would have produced [[alpha-propiolactone]], a lactone with a 3-membered ring.

In 1880 the German chemist [[Wilhelm Rudolph Fittig]] extended the name "lactone" to all intramolecular carboxylic esters.<ref>{{cite journal |last1=Fittig |first1=Rudolph |title=Untersuchungen über ungesättige Säuren, dritte Abhandlung |journal=Annalen der Chemie und Pharmacie |date=1880 |volume=200 |pages=1–96 |doi=10.1002/jlac.18802000102 |url=https://babel.hathitrust.org/cgi/pt?id=uiug.30112025844553&view=1up&seq=72 |trans-title=Investigations into unsaturated acids, third article |language=de}}  From p. 62:  ''"Es ist wünschenswerth, für diese Gruppe von Verbindungen, deren bis jetzt einfachster Repräsentant der im Vorstehenden beschriebene Körper ist, eine allgemeine Bezeichnungsweise zu haben, und da der Name "Lactide" nicht anwendbar ist, weil dann das Lactid κατ εξοχην kein Lactid sein wurde, so schlagen wir als Gruppenbezeichnung den Namen "Lactone" vor".'' (It's desirable for this group of compounds — whose simplest representative until now has been the substance that's described in the preceding — to have a general designation, and since the name "lactide" isn't applicable because then the archetypal lactide would not be a lactide, we therefore suggest the name "lactone" as the designation of this group [of compounds].)</ref>