Trost Barry M, Rudd Michael T
Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
J Am Chem Soc. 2002 Apr 24;124(16):4178-9. doi: 10.1021/ja012672a.
CpRu(NCCH3)3+PF6- catalyzes the cycloisomerization of diyne-ols to alpha,beta,gamma,delta-unsaturated aldehydes and ketones in good-to-excellent yields. 1-Hydroxy-2,7-diynes and 1-hydroxy-2,8-diynes can be utilized to form highly functionalized five- and six-membered rings, respectively. Tertiary as well as secondary propargyl alcohols are cycloisomerized to a single isomeric product. A wide variety of tether substitution can be tolerated. Even totally unsubstituted tethers can be employed, as geminal disubstituents are not required for cyclization. Additional hydroxyl substituents at an alternative "internal" propargylic position are eliminated during the reaction-a feature that leads to a convenient cyclopentadiene synthesis. Furthermore, 3-hydroxy-1,6-diynes also can be cyclized to form cross-conjugated aldehydes.
CpRu(NCCH3)3+PF6-催化二炔醇环异构化为α,β,γ,δ-不饱和醛和酮，产率良好至优异。1-羟基-2,7-二炔和1-羟基-2,8-二炔可分别用于形成高度官能化的五元环和六元环。叔炔丙醇和仲炔丙醇都环异构化为单一的异构体产物。可以耐受多种连接基取代。甚至完全未取代的连接基也可使用，因为环化不需要偕二取代基。在反应过程中，另一个“内部”炔丙基位置上的额外羟基取代基会被消除——这一特点导致了一种简便的环戊二烯合成方法。此外，3-羟基-1,6-二炔也可环化形成交叉共轭醛。
