Bispericyclic Diels–Alder Dimerization of <i>ortho</i> ‐Quinols in Natural Product (Bio)Synthesis: Bioinspired Chemical 6‐Step Synthesis of (+)‐Maytenone

Many natural products of plant or microbial origins are derived from enzymatic dearomative oxygenation 2-alkylphenolic precursors into 6-alkyl-6-hydroxycyclohexa-2,4-dienones. These so-called ortho-quinols cyclodimerize via a remarkably selective bispericyclic Diels–Alder reaction. Whether not the intervention catalytic dirigent proteins is involved during this final step biosynthesis these products, cyclodimerization can be chemically reproduced in laboratory with same strict level site-specific regioselectivity and stereoselectivity. This unique yet unified process, which finds its rationale inherent chemical reactivity those ortho-quinols, illustrated herein by an efficient bioinspired first synthesis one most structurally complex synthetically challenging examples such cyclodimers, bisditerpenoid (+)-maytenone.