Lithium Organochalcogenides Promoting Michael-aldol Tandem Reactions

Scheme 1. Standard reaction conditions for the three component protocol and some exemples of the obtained adducts. We also investigated the possibility to perform a one-pot trapping of the intermediate alcoxide anion from the aldol reaction with carboxylic acid chlorides. The sequential procedure allows performing in a single flask the Michael-aldol, acylation and chalcogen elimination reactions resulting in the corresponding acylated BayllisHillman adducts in very good yields. In addition, these compounds can be converted in highly substituted six-membered ring lactones as shown in Scheme 2.