Biomimetic conversion of aconitine-type C19-diterpenoid alkaloids to lactone-type alkaloids

The first biomimetic conversion from the aconitine-type C₁₉-diterpenoid alkaloids to the corresponding alkaloids of lactone-type C₁₉-diterpenoid alkaloid has been achieved. Chasmanine was used as starting material with Baeyer–Villiger oxidation as a key reaction. It was also observed that the oxygenated group at C-16 did not change the relative migration tendencies of C-13 and C-9 during the oxidation. Meantime, a novel D-ring fragmented compound was obtained during the course of the present investigation. The plausible mechanism of the formation of this compound was also proposed.