Asymmetric Total Syntheses of 8,9‐Seco‐<i>ent</i>‐kaurane Diterpenoids Enabled by an Electrochemical ODI‐[5+2] Cascade
Bingnan Wang, Zhaobo Liu, Zhenzhong Tong, Beiling Gao, Hanfeng Ding
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.
Topics & Concepts
Aldol reactionChemistryCascadeElectrochemistryStereochemistryTotal synthesisAldol condensationCombinatorial chemistryBicyclic moleculeOrganic chemistryCatalysisPhysical chemistryElectrodeChromatographyBioactive Natural Diterpenoids ResearchMarine Sponges and Natural ProductsTraditional and Medicinal Uses of Annonaceae