Journal
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
Volume 141, Issue 20, Pages 8372-8380Publisher
AMER CHEMICAL SOC
DOI: 10.1021/jacs.9b03978
Keywords
-
Categories
Funding
- Beijing Municipal Science & Technology Commission [Z181100001318008]
- MOST of China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University
Ask authors/readers for more resources
Structurally complex and bioactive ent-kaurane diterpenoids have well-characterized biological functions and have drawn widespread attention from chemists for many decades. However, construction of highly oxidized forms of such diterpenoids still presents considerable challenges to synthetic chemists. Herein, we report the first total syntheses of C19 oxygenated spiro-lactone ent-kauranoids, including longirabdiol, longirabdolactone, and effusin. A concise synthesis of the common intermediate used for all three syntheses was enabled via three free-radical-based reactions: (1) a newly devised tandem decarboxylative cyclization/alkenylation sequence that forges the cis-19, 6-lactone concomitantly with vicinal alkenylation, (2) a Ni-catalyzed decarboxylative Giese reaction that constructs C10 quaternary center stereoselectively, and (3) a vinyl radical cyclization that generates a rigid bicyclo[3.2.1]octane. A series of late-stage oxidations from the common intermediate then provided each of the natural products in turn. Further biological evaluation of these synthetic natural products reveals broad anticancer activities.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available