Gas phase thermalisomerizations of twelve acetylenic systems, all of which can in principle undergo two successive pericyclic steps, are described. The substrates, the syntheses and spectroscopic properties of which are presented, are formal derivatives of but-2-yne, with different functional groups in the 1- and the 4-positions. The Cope, Claisen, Claisen ester, retro-ene, 1,5-hydrogen shift, and
Etude du comportement d'organometalliques (M = Zn, Mg, Li) vis a vis d'enynes conjuges
作者:D. Mesnard、L. Miginiac
DOI:10.1016/s0022-328x(00)87262-9
日期:1976.9
organometallic compounds such as allyl-zinc, -magnesium, -lithium and saturated lithium compounds are shown to readily undergo addition reactions with conjugated enynes: HCCC(R)C(R)(R), but the reactivity is reduced when the steric hindrance around the double bond is increased. With each organometallic compound used, this reaction is regioselective: 3,4 addition with organozinc compounds, 1,2 addition