Asymmetric Total Syntheses of 8,9-Seco-ent-kaurane Diterpenoids Enabled by an Electrochemical ODI-[5+2] Cascade

Bingnan Wang; Zhaobo Liu; Zhenzhong Tong; Beiling Gao; Hanfeng Ding

doi:10.1002/anie.202104410

Asymmetric Total Syntheses of 8,9-Seco-ent-kaurane Diterpenoids Enabled by an Electrochemical ODI-[5+2] Cascade

Angew Chem Int Ed Engl. 2021 Jun 25;60(27):14892-14896. doi: 10.1002/anie.202104410. Epub 2021 Jun 4.

Authors

Bingnan Wang¹, Zhaobo Liu¹, Zhenzhong Tong¹, Beiling Gao¹, Hanfeng Ding^{1

2}

Affiliations

¹ Department of Chemistry, Zhejiang University, Hangzhou, 310058, China.
² State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, China.

PMID: 33900670
DOI: 10.1002/anie.202104410

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.

Keywords: cascade reactions; electrochemistry; sigmatropic rearrangement; terpenoids; total synthesis.

Publication types

Research Support, Non-U.S. Gov't