Department of Chemistry , University of California, Berkeley , 826 Latimer Hall , Berkeley , California 94720 , United States.
J Am Chem Soc. 2019 Feb 20;141(7):3083-3099. doi: 10.1021/jacs.8b12247. Epub 2019 Feb 11.
The Illicium sesquiterpenes are a family of natural products containing over 100 highly oxidized and structurally complex members, many of which display interesting biological activities. This comprehensive account chronicles the evolution of a semisynthetic strategy toward these molecules from (+)-cedrol, seeking to emulate key aspects of their presumed biosynthesis. An initial route generated lower oxidation state analogs but failed in delivering a crucial hydroxy group in the final step. Insight gathered during these studies, however, ultimately led to a synthesis of the pseudoanisatinoids along with the allo-cedrane natural product 11- O-debenzoyltashironin. A second-generation strategy was then developed to access the more highly oxidized majucinoid compounds including jiadifenolide and majucin itself. Overall, one dozen natural products can be accessed from an abundant and inexpensive terpene feedstock. A multitude of general observations regarding site-selective C(sp)-H bond functionalization reactions in complex polycyclic architectures are reported.
倍半萜烯是一类天然产物，包含 100 多种高度氧化和结构复杂的成员，其中许多具有有趣的生物活性。本综述追溯了从 (+)-柏木醇出发的针对这些分子的半合成策略的发展，旨在模拟其假定生物合成的关键方面。最初的路线生成了较低氧化态的类似物，但在最后一步未能提供关键的羟基。然而，在这些研究中收集的见解最终导致了伪异土木香内酯和 allo-cedrane 天然产物 11-O-去苯甲酰基他西罗宁的合成。然后开发了第二代策略来获得更高度氧化的 majucinoid 化合物，包括 jiadifenolide 和 majucin 本身。总的来说，从丰富且廉价的萜烯原料可以获得十二种天然产物。报道了针对复杂多环结构中环 C(sp)-H 键的选择性功能化反应的大量一般性观察结果。
