Total Synthesis of (−)‐ and ent‐(+)‐Vindorosine: Tandem Intramolecular Diels–Alder/1,3‐Dipolar Cycloaddition of 1,3,4‐Oxadiazoles

From tandem to pentacycle: The intramolecular tandem [4+2]/[3+2] cycloaddition cascade of 1,3,4-oxadiazole (Z)-1 to give the pentacyclic skeleton 2 of (−)- and ent-(+)-vindorosine introduces all the requisite substituents and functionality in a single step by which three new rings and four CC bonds form and all six key stereocenters are installed.