A Simple Synthesis of 3,5- and 2,3,5-Alkyl- or -Aryl-Substituted Thiophenes α-Bromo- and α-chloroalkanones react readily with tert-butylmercaptan according to Lissel1 to give 2-(tert-butylthio)ketones. Reaction of these ketones with the 1-alkynylmagnesium halides derived from phenylacetylene or 1-hexyne affords unstable mixtures of stereoisomeric 2-(tert-butylthio)-1-(1-alkynyl)alkanols which, upon treatment with hot aqueous acid, give 3,5-di- or 2,3,5-trisubstituted thiophenes in overall yields from 36 to 90%.
简单合成3,5-和2,3,5-烷基或芳基取代的
噻吩。α-
溴-和α-
氯烷酮与
叔丁基硫醇根据Lissel的研究反应生成2-(叔丁基
硫)酮。这些酮与源自
苯乙炔或
1-己炔的1-炔基卤化
镁反应,形成不稳定的立体异构体混合物2-(叔丁基
硫)-1-(1-炔基)醇,经过热
水酸处理后,最终生成3,5-二取代或2,3,5-三取代的
噻吩,总产率在36%到90%之间。