I found the field of Chemistry very interesting. Saw the article Dienolates of Cycloalkenones and alpha,beta-Unsaturated Esters Form Diels-Alder Adducts by a Michael/Michael-Tandem Reaction Rather Than in One Step published in 2019. Recommanded Product: (E)-2-Methylbut-2-enoic acid, Reprint Addresses Bruckner, R (corresponding author), Albert Ludwigs Univ, Inst Organ Chem, Albertstr 21, D-79104 Freiburg, Germany.. The CAS is 80-59-1. Through research, I have a further understanding and discovery of (E)-2-Methylbut-2-enoic acid
,-Unsaturated esters and lithium 1,3-dien-2-olates are known to furnish bicyclic lithium enolates by anionic Diels-Alder reactions. However, in principle, the respective products might form not only in a single step but also in two consecutive – or tandem – Michael additions, the first of which occurs intermolecularly, the second intramolecularly. Three cyclic lithium dienolates and four esters with a stereogenic C=C bond reacted to give Diels-Alder adducts (10 times) or failed to react (2 times). Seven of the reactive combinations furnished adducts wherein the configuration of the former ester moiety had in part inverted. This precludes concerted pathways as their origins. This was a surprise since donors at C-2 of the 1,3-diene accelerate normal electron-demand Diels-Alder reactions in the order alkyl < aryl < alkoxy approximate to trialkylsiloxy < acylamino. With (LiO?)-O-circle plus being a far better donor still, it is not obvious why the mechanism is non-concerted rather than concerted (and still more asynchronous). Welcome to talk about 80-59-1, If you have any questions, you can contact Loesche, AC; Bruckner, R or send Email.. Recommanded Product: (E)-2-Methylbut-2-enoic acid
Reference:
Indole alkaloid derivatives as building blocks of natural products from Bacillus thuringiensis and Bacillus velezensis and their antibacterial and antifungal activity study,
,Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles