Total syntheses of several iridolactones and the putative structure of noriridoid scholarein A: An intramolecular Pauson-Khand reaction based one-stop synthetic solution

Abstract

A simple and general approach towards the total syntheses of several iridolactones such as (�)-boschnialactone, (�)-7-epi-boschnialactone, (�)-teucriumlactone, (�)-iridomyrmecin, (�)-isoboonein, (�)-7-epi-argyol, (�)-scabrol A, (�)-7-epi-scabrol A, and (�)-patriscabrol as well as the putative structure of scholarein A is delineated. The synthetic strategy features a diastereoselective intramolecular Pauson-Khand reaction (IPKR) to construct the iridoid framework followed by some strategic synthetic manipulations to access the targeted monoterpenes including those having diverse oxy-functionalization patterns and with 3-5 contiguous stereogenic centres in a highly stereocontrolled manner. Also, the present endeavour includes the first total synthesis of scabrol A. � The Royal Society of Chemistry 2019.