Selective Synthesis of Functionalized 3(2H)‐Furanones via Tandem MichaelAddition/Rearrangement/Cyclization Reaction of Aliphatic Alkynones: A Combined Experimental and Theoretical Study

Abstract A novel catalyst‐ and solvent‐controlled dimerization of aliphatic alkynones through tandem Michael addition/rearrangement/cyclization sequence has been developed. The elaborated protocol provides a convenient chemo‐, regio‐ and stereoselective access to rare 3(2 H )‐furanones decorated with 2‐ exo ‐methylene and 4‐ethenyl functionalities. A comprehensive density functional theory (DFT) study of possible reaction mechanism including ab initio molecular dynamics (AIMD) simulations and quantum theory of atoms in molecules (QTAIM) analysis of various substrate/catalyst/solvent complexes has revealed the Janus‐like behavior of the employed sodium tert ‐butoxide/toluene system that is responsible both for the chemoselectivity of the initial addition step and the inhibition of the final cyclization step.