Partial synthesis of C-ring derivatives from oleanolic and maslinic acids. Formation of several triene systems by chemical and photochemical isomerization processes
作者:Andrés Garcı́a-Granados、Pilar E López、Enrique Melguizo、Andrés Parra、Yolanda Simeó
DOI:10.1016/j.tet.2003.12.023
日期:2004.2
Some triterpenic compounds modified in C-ring were semi-synthesised from oleanolic acid contained in the solid waste of olive-oil pressing. The corresponding esters of oleanolic and maslinic acids rendered products with a diene system, which led to oleantrienes resembling previtamin D2 by an electrocyclic reaction. Chemical and photochemical isomerization of these compounds yielded two different trienes
Reductive Aldol Approach to Natural Products: Bioinspired Synthesis of <i>abeo</i>-11(12 → 13)-Oleanane Triterpenoids
作者:Ruoxi Li、Jingjing Wu
DOI:10.1021/acs.orglett.3c02076
日期:2023.9.1
A synthesis of alstoscholarinoid B (1) and 3β-acetoxy-11α-hydroxy-11(12 → 13)abeooleanan-12-al (2) has been accomplished in 7–9 steps and 10%–16% overall yield from oleanolic acid. This synthesis featured a bioinspired SmI2-mediated reductive aldol reaction to establish the abeo-11(12 → 13)-oleanane framework of both 1 and 2 and a retro-aldol/aldol/lactonization cascade to fully construct the skeleton