Facile Synthesis of 3-Benzylidene-5-aryl-3H-furan-2-ones Starting from the Baylis-Hillman Adducts

Abstract

Recently we reported the synthesis of 3-arylidenelactams and 3-arylidenelactones starting from the Baylis-Hillman adducts via the following sequences: (i) preparation of cinnamyl bromide from the Baylis-Hillman adducts, (ii) generation of sulfur ylide (Me2S/K2CO3) and the following reaction with N-tosylimine to produce N-tosylaziridine, (iii) LiClO4-assisted ring-opening reaction with aniline and the cyclization to 3-arylidenelactam or LiClO4-assisted intramolecular lactonization and concomitant aziridine-opening reaction to 3-arylidenelactone. 1 The reaction sequence is depicted in Scheme 1. In this communication, we wish to report another expeditious route for the synthesis of 3-benzylidenelactone compounds 5 and 3-benzylidene-5-aryl-3H-furan-2-ones 6.