2-Vinylfuran derivatives undergo regiocontrolled PausonâKhand
reaction, in which the furan exerts the dominant directing influence, to
furnish 5-(2-furyl)cyclopent-2-enones, overwhelming the strong directing
effects of a homoallylic thioether and appearing to inhibit intramolecular
reaction in which bridging constraints are in opposition to the directing
influence of the 2-furyl substituent.
2-乙烯基呋喃衍
生物发生了受区域控制的保森汉德反应,在该反应中,
呋喃发挥了主要的指导作用,生成了 5-(2-
呋喃基)环戊-2-烯酮,压倒了同烯丙基
硫醚的强烈指导作用,并似乎抑制了分子内反应,在分子内反应中,桥接约束与 2-
呋喃基取代基的指导作用相反。