An Efficient Procedure for the Preparation of (<i>E</i>)-α-Alkylidenecycloalkanones Mediated by a CeCl<sub>3</sub>·7H<sub>2</sub>O−NaI System. Novel Methodology for the Synthesis of (<i>S</i>)-(−)-Pulegone<sup>1</sup>
synthons used as the key intermediates in many important syntheses. Because of their potential, a general method of preparation from readily available starting materials, under very mild conditions, was considered to be worthwhile. Cerium(III) chlorideheptahydrate in combination with sodiumiodide in refluxing acetonitrile promotes a regio- and stereoselective beta-elimination reaction to (E)-2-alky