作者:Kenta Rakumitsu、Jukiya Sakamoto、Hayato Ishikawa
DOI:10.1002/chem.201902073
日期:2019.7.5
bioinspired divergent syntheses of monoterpenoid indole alkaloids, was prepared in gram‐scale in seven steps. The total syntheses of 2 and 3, which are classified as glycosylated monoterpenoid indole alkaloids, were achieved through bioinspired transformations such as a diastereoselective Pictet–Spengler reaction, a site‐ and stereoselective epoxidation, and a site‐selective epoxide ring‐opening followed
(-)-secologanin(1),(-)-5-羧基缩水嘧啶(2)和(-)-紫丁烯碱(3)的第一个对映选择性全合成分别通过10、9和14个步骤完成。合成1的关键转变是顺序的反选择性有机催化迈克尔反应/福山还原/自发环化反应,形成旋光的二氢吡喃环。此外,以七步法制备了以克级规模制备的单萜类吲哚生物碱,是生物启发性合成发散合成的潜在关键中间产物四乙酸secologanin(四乙酸)(16)。2和3的总合成通过生物启发性转化,例如非对映选择性Pictet-Spengler反应,定点和立体选择性环氧化,以及定点选择性环氧化物开环和内酯化反应,实现了被归类为糖基化的单萜类吲哚生物碱。