Pictet-spengler reactions in aprotic media. The total synthesis of (±) suaveoline
作者:Mark L. Trudell、Dave Soerens、Robert W. Weber、Larry Hutchins、Desiree Grubisha、Dennis Bennett、James M. Cook
DOI:10.1016/s0040-4020(01)88507-0
日期:1992.1
The first total synthesis of the indole alkaloid (±)-suaveoline 1 (a macroline-related base and a member of the sarpagine/ajmaline class of alkaloids) was completed in a stereocontrolled fashion. The serial synthesis employed three intramolecular reactions, the Pictet-Spengler cyclization (11 → 20), the Dieckmann condensation (21 → 22) and the orthoester Claisen rearrangement (25 → 30), all of which
吲哚生物碱(±)-suaveoline 1(一种与大线相关的碱,是一种沙培胺/ ajmaline类生物碱的成员)的第一个全合成以立体控制方式完成。系列合成采用三个分子内反应:Pictet-Spengler环化(11 → 20),Dieckmann缩合(21 → 22)和原酸酯克莱森重排(25 → 30),所有这些反应均具有较高的立体选择性。独特的3,4,5-三取代的吡啶环的构建(Ë的)1通过将盐酸羟胺加到相应的1,5-二醛36的乙醇溶液中,随后加热来进行。在甲酸的存在下,通过催化脱酶作用(Pd / C,H 2),由37从(37)制备相关的碱(±)-N b-甲基suaveoline 38(收率78%)。