Lan Ping, Banwell Martin G, Willis Anthony C
Department of Food Science and Engineering , Jinan University , Guangzhou , 510632 , China.
Research School of Chemistry , Institute of Advanced Studies, The Australian National University , Canberra , ACT 2601 , Australia.
J Org Chem. 2018 Aug 3;83(15):8493-8498. doi: 10.1021/acs.joc.8b01088. Epub 2018 Jun 7.
Crinane embodies the tetracyclic framework associated with some of the most common Amaryllidaceae alkaloids. It has now been prepared in 10 steps from 6,6-dibromobicyclo[3.1.0]hexane (2). The initial step involves the thermally induced electrocyclic ring opening of cyclopropane 3 and capture of the resulting π-allyl cation with benzylamine to give an allylic amine that is readily elaborated to the 3°-amine 10. This last compound was engaged in a 5- exo- trig free radical cyclization reaction to give the C3a-arylated perhydroindole 11. Compound 11 was then converted, over two steps, into (±)-crinane, the hydrochloride salt of which has been subjected to single-crystal X-ray analysis.
克里南烷体现了与一些最常见的石蒜科生物碱相关的四环骨架。现在已从6,6 - 二溴双环[3.1.0]己烷（2）经10步反应制备得到它。第一步涉及环丙烷3的热诱导电环化开环，并用苄胺捕获生成的π - 烯丙基阳离子，得到一种烯丙基胺，该烯丙基胺可容易地转化为叔胺10。最后一种化合物进行了5 - 外向 - 三角自由基环化反应，得到C3a - 芳基化的全氢吲哚11。然后化合物11经两步反应转化为（±） - 克里南烷，其盐酸盐已进行单晶X射线分析。
