For successive C-alkylation, using NaOMe/MeOH, followed by NaH/THF, see: Org. Synth. Coll., 8, 381 (1993). For Michael addition to ɑ?-unsaturated acids, catalyzed by the Li salt of L-proline, see: J. Chem. Soc., Chem. Commun., 1088 (1991). For Knoevenagel reaction with (R)-citronellal, catalyzed by piperidine/AcOH, to give the alkylidene derivative, see: Org. Synth. Coll., 9, 310 (1998). C-Arylation with ortho-nitroaryl halides can be accomplished with NaH in DMSO. The products can be readily converted to substituted oxindoles: Synthesis, 51 (1993). Arylation with benzene: Tetrahedron Lett., 27, 2763 (1986), and free-radical substitution with thiophene or furan at the 2-position: Heterocycles, 27, 2627 (1988), are promoted by Ce(IV) salts.
