BioinspiredSynthesis of Microstegiol and BiosyntheticallyRelated Skeleton-Rearranged Abietanes

We report a bioinspired synthesis of microstegiol and biosynthetically related skeleton-rearranged abietane diterpenoids from commercially available carnosic acid. The strategy features a Wagner–Meerwein type methyl migration followed by several cascade transformations, enabling the divergent synthesis of five abietane diterpenoids, including viridoquinone, prattinin A, saprorthoquinone, microstegiol, and 1-deoxyviroxocin.