A Facile Preparation of <i>e</i><i>xo</i>-Cyclic Conjugated Dienes Fused to Lactams or Lactones via Intramolecular Coupling of Acetylenes and Their Behavior in Diels−Alder Reactions
作者:Hirokazu Urabe、Ryota Nakajima、Fumie Sato
DOI:10.1021/ol0065221
日期:2000.11.1
[reaction: see text] Treatment of bis-acetylenic amides or esters 3 with (eta(2)-propene)Ti(O-i-Pr)(2) generates functionalized titanacyclopentadienes which, upon hydrolytic workup, give exo, exo-cyclic conjugated dienes 4 in good yields. Some regio- and stereochemical aspects of their Diels-Alder reaction with dienophiles are also disclosed.
[反应:参见正文]用(eta(2)-丙烯)Ti(Oi-Pr)(2)处理双炔酰胺或酯3生成官能化的钛环戊二烯,经水解后,可得到外,外环共轭二烯4个单产好。还公开了它们与亲双烯体的Diels-Alder反应的一些区域和立体化学方面。