Synthesis of Vinylallenes by Conjugate 1,6-, 1,8-, 1,10- and 1,12-Addition Reactions of Organocuprates with Acetylenic Michael Acceptors and Their Use as Dienes in Intermolecular Diels-Alder Reactions
作者:Ulrich Koop、Gabriele Handke、Norbert Krause
DOI:10.1002/jlac.199619961002
日期:1996.10
Various vinylallenes were synthesized by conjugate cuprate additions to acetylenic Michael acceptors. Thus, 1,6-addition reactions with 2-en-4-ynoates 1, 3, and 5a, respectively, furnished vinylallenes 2, 4, and 7 after regioselective electrophilic capture of the allenyl enolates formed. Likewise, 1,8-addition to 2,4-dien-6-ynoates 8a and 10 gave the vinylallenes 9 and 11, whereas the 1,10-addition
通过共轭铜酸酯加成到炔属迈克尔受体上,合成了各种乙烯基烯丙二烯。因此,分别与2-en-4-酸酯1、3和5a进行1,6-加成反应后,形成区域的烯丙基烯醇盐进行了区域选择性亲电捕获,从而得到了乙烯基亚烷基2、4和7。同样地,向2,4-二烯-6-壬酸酯8a和10加成1,8 ,得到乙烯基烯丙基9和11,而向2,4,6-三烯-8-壬酸酯中加成Me 2 CuLi的1,10。图12提供了丙二烯13,以及向2,4,6,8-四烯基-10ynoate 14的类似的1,12加成。装备了多烯15。这些乙烯基丙二烯在区域和立体选择性Diels-Alder反应中是有价值的亲二烯体,如环加成产物16-24的形成所证明。在路易斯酸的存在下,乙烯基亚丙基4a大概重排为环戊二烯衍生物,其随后形成环加合物25和26。