Photoinduced vinylcyclopropane-cyclopentene rearrangement: A methodology for chiral bicyclo[3.2.0]heptenes. Formai syntheses of (±)-grandisol and naturally occurring ()-Δ9(12)-Capnellene and its antipode
作者:Harikisan R. Sonawane、Vishwaniyant G. Naik、Nanjundiah S. Bellur、Virendra G. Shah、Pramod.C. Purohit、M.Uday Kumar、Dilip G. Kulltarni、Jaimala R. Ahuja
DOI:10.1016/s0040-4020(01)91019-1
日期:1991.9
The problem of achieving reaction selectivity in -alkyl vinylcyclopropanes in favour of their rearrangement to cyclopentenes, obviating the competing low energy process of the [1,5] (homo) sigmatropic hydrogen shift, is addressed. It has been demonstrated that the readily available bicyclo[4.1.0]heptenes derived from (+)-Δ3-carene. (1), upon photosensitized irradiation, are conveniently transformed
解决了在-烷基乙烯基环丙烷中实现反应选择性而有利于重排成环戊烯的问题,从而避免了竞争性的[1,5](均质)σ向氢转移的低能过程。已经证明的是,容易获得的二环[4.1.0]衍生自庚烯(+) - Δ 3 -carene。(1)在光敏辐射下,方便地转化为手性-双环[3.2.0]庚烯。这种策略的合成潜力已在实现了重要的昆虫信息素的高效合成正规的被证实(±)-grandisol(2)和两个对映体Δ 9(12) -capnellene(3从容易获得的)1,印度松节油的主要成分。