Asymmetric Total Syntheses of 8, 9‐Seco‐ent‐kaurane Diterpenoids Enabled by an Electrochemical ODI‐[5+2] Cascade. Issue 27 (4th June 2021)

• Record Type: Journal Article
• Authors: Wang, Bingnan; Liu, Zhaobo; Tong, Zhenzhong; Gao, Beiling; Ding, Hanfeng
• Is Part Of: Angewandte Chemie international edition. Volume 60:Issue 27(2021)
• Page Start: 14892
• Page End: 14896
• Publication Date: 2021-06-04
• Subjects: cascade reactions -- electrochemistry -- sigmatropic rearrangement -- terpenoids -- total synthesis; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202104410
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: An electrochemical ODI‐[5+2] cascade reaction was developed which enables the rapid assembly of diversely functionalized bicyclo[3.2.1]octadienones from sensitive ethynylphenols. By combining a directed retro‐aldol/aldol process, a [2, 3]‐sigmatropic rearrangement, and an Al(O‐iPr)3 ‐promoted reductive 1, 3‐transposition, the asymmetric total syntheses of five 8, 9‐seco‐ent‐kauranoids—(−)‐shikoccin, (−)‐O‐methylshikoccin, (−)‐epoxyshikoccin, (+)‐O‐methylepoxyshikoccin, and (+)‐rabdo‐hakusin—have been achieved in a concise and efficient manner. Abstract : An efficient ODI‐[5+2] cascade reaction of sensitive ethynylphenols was achieved under mild electrochemical conditions, which led to the rapid construction of a series of bicyclo[3.2.1]octadienone skeletons. By incorporation of a directed retro‐aldol/aldol process, a [2, 3]‐sigmatropic rearrangement and an Al(O‐ i Pr)3 ‐promoted reductive 1, 3‐transposition, the asymmetric total syntheses of five 8, 9‐seco‐ ent ‐kauranoids have been accomplished.