Toward the Total Synthesis of Myrindole A: Assembly of Fully Functionalized Cyclohexenone

A rapid installation of the highly functionalized six-membered carbocycle-based core embedded in the central position of myrindole A was reported. Key transformations include (1) an intramolecular Diels–Alder reaction with N-substituted 2-oxazolone as the dienophile to directly introduce the structurally complex tetracyclic subunit characterized with four continuous stereocenters (one quaternary), (2) an air-promoted multifold cascade reaction to realize the formal remote C–H oxidation, and (3) an unprecedented ring contraction to finish the creation of the fully functionalized cyclohexenone nucleus via formal 1,2-trans migration of the ArO group. The possible reaction pathways for the aforementioned transformations were tentatively put forward.