Total Synthesis of Shearinines D and G: A Convergent Approach to Indole Diterpenoids

The first total syntheses of the indole diterpenoids (+)-shearinine G and D are disclosed. successful routes rely on late-stage coupling two complex fragments. Formation challenging trans-hydrindane motif was accomplished by diastereoselective, intramolecular cyclopropanation. A one-pot sequence consisting Sharpless dihydroxylation/Achmatowicz reaction developed to install dioxabicyclo[3.2.1]octane motif. indenone subunit accessed Prins cyclization. Tuning electronic nature substituents parent arylcarboxaldehyde allowed access divergent products that were further transformed into shearinines D. Riley-type oxidation a bicyclic enone yielded surprising stereochemical outcome.