Diels-Alder reaction of α-substituted acrylates and α-(methylene)lactones: Conformation of dienophiles and endo/exo selectivity
作者:Kei Takeda、Ikuhiro Imaoka、Eiichi Yoshii
DOI:10.1016/s0040-4020(01)85696-9
日期:1994.1
Diels-Alder reaction of 1,6-bis(trimethylsilyloxy)-2,4-hexadiene with α-substituted acrylates and 5 to 7- and 9 to 11-membered α-(methylene)lactones has been carried out to examine correlation of dienophile structure with endo/exo selectivity. While the conformationally flexible acrylates produced cycloadducts of endo/exo = 59:41 to 74:26, the 5 to 7-membered lactones with rigid s-cis conjugate system
1,6-双(三甲基甲硅烷氧基)-2,4-己二烯与α-取代的丙烯酸酯以及5至7和9至11元的α-(亚甲基)内酯的Diels-Alder反应已经进行,以检验亲二烯体的相关性具有内/外选择性的结构。构象柔性丙烯酸酯可生成内/外环的加合物= 59:41至74:26,具有刚性s-顺式共轭体系的5至7元内酯可提供内/外环的13:87至32:68的高聚物。可以同时具有s-顺式和s-反式构象的9至11元内酯提供的内/外比为37:63至57:43。