Synthesis of 12-<i>epi</i>
-Protopanaxadiol and Formal Synthesis of Ginsenoside Chikusetsusaponin-LT<sub>8</sub>
作者:Laurent Evanno、Damien Belotti、Edmond Toromanoff、Janine Cossy
DOI:10.1002/ejoc.201901031
日期:2019.9.15
For the total synthesis of protopanaxadiol: (1) an optically active trienic epoxide was submitted to Ti‐(III)‐mediated radical cascade to afford an original 6/6/8/5 tetracyclic structure; (2) using a “ring‐by‐ring” synthesis gave access to 12‐epi‐protopanaxadiol. 20‐Hydroxydammar‐24‐ene‐3,12‐dione was also synthesized, which represents a formal synthesis of chikusetsusaponin‐LT8, isolated from Panax
对于原萘甲二醇的全合成:(1)将光学活性的三烯环氧化物送入Ti-(III)介导的自由基级联反应,得到原始的6/6/8/5四环结构;(2)使用“逐环”合成方法可获得12-表位-原-萘并萘二酚。还合成了20-羟基达玛尔-24-烯-3,12-二酮,其代表从日本三七分离的chikusetsusaponin-LT 8的正式合成。