Preparation andDiels-Alder Reactivity of 2,3,5,6,7,8-Hexamethylidenebicyclo [2.2.2]octane (?[2.2.2]Hericene?). Force-field calculations of exocyclic dienes as a moiety of bicyclic skeletons
作者:Olivier Pilet、Jean-Luc Birbaum、Pierre Vogel
DOI:10.1002/hlca.19830660103
日期:1983.2.2
cycloadditions of 2,3,5,6-tetramethylidene-bicyclo [2.2.2]octane (3) giving the corresponding monoadducts 23 and 27 (k1) and bis-adducts 25 and 29 (k2) with TCE and DMAD, respectively. Constrastingly, the rate constant ratio k2/k3 is relatively large as the rate constant ratio k1/k2 of the Diels-Alder additions for 5,6,7,8-tetramethylidenebicyclo [2.2.2]oct-2-ene (4) giving the corresponding monoadducts 24 and
由香豆酸和马来酸酐经八步制备了[2.2.2]烯(6),它是带有三个环外顺-顺-丁二烯单元的双环[2.2.2]辛烷。己烯6相继加入三个摩尔当量。强亲二烯体,例如亚乙基四甲腈(TCE)和乙酰二羧酸二甲酯(DMAD),分别给出相应的单加合物17和20(k 1),双加合物18和21(k 2)和三加合物19和22(k 3) 。速率常数比k1 / k 2小,如2,3,5,6-四亚甲基-双环[2.2.2]辛烷(3)的环加成反应,得到相应的单加合物23和27(k 1)和双加合物25 TCE和DMAD分别为29和(k 2)。相反,当5,6,7,8-四亚甲基双环[2.2.2] oct-2-ene的Diels-Alder加成物的速率常数比k 1 / k 2时,速率常数比k 2 / k 3相对较大。(4)给出相应的单加合物24和28(k 1)和双加合物26和30(k 2)。对于TCE添加,获得了以下二阶速率常数(甲苯,25°)和活化参数:3