Ie. Marko et Gr. Evans, DIASTEREOSELECTIVE, LANTHANIDE-CATALYZED, INVERSE ELECTRON-DEMAND DIELS-ALDER (IEDDA) REACTIONS OF 3-CARBOMETHOXY-2-PYRONE (3-CMP) DERIVATIVES, Tetrahedron letters, 35(17), 1994, pp. 2767-2770
Cycloaddition reactions between the chiral 2-pyrone derivatives 3 and
various dienophiles, catalysed by lanthanide shift reagents, afford bi
cyclic lactones 8 in high diastereomeric excesses.