1. Organic Syntheses via Transition Metal Complexes. 85.1 [2-(Alkenyloxy)ethenyl]- and [2-(Aryloxy)ethenyl]carbene Complexes from (1-Alkynyl)carbene Complexes of Chromium and Tungsten and Their Fragmentation to 2,4-Dien-5-ones
2. For reviews of synthetic strategies toward five-membered carbocycles see: (a) Paquette, L. A.Top. Curr. Chem.1979,79, 41−165;1984,119, 1−158. (b) Ramaiah, M.Synthesis1984, 529−570. (c) Little, R. D. InComprehensive Organic Synthesis; Trost, B. M., Fleming, I., Eds.; Pergamon: Oxford, 1991; Vol. 5, pp 239−270. (d) Chan, D. M. T.Ibid; Vol. 5, pp 271−314. (e) Denmark, S. E.Ibid; Vol. 5, pp 751−784.
3. The khand reaction