A phloroglucinol derivative with a new carbon skeleton from Hypericum perforatum (Guttiferae)

Examination of the aerial parts of a Chinese herbal medicine yielded a novel metabolite, perforatumone 1, which is characterized by its unique carbon skeleton. Its structure was determined by detailed spectroscopic analysis.     

A new approach for the construction of a highly congested bicyclic system in polycyclic polyprenylated acylphloroglucinols (PPAPs)

A highly congested bicyclo[3.3.1]nonanone core of polycyclic polyprenylated acylphloroglucinols was constructed using a stereoselective Claisen rearrangement and an intramolecular aldol reaction as the key steps. The stereochemistry of C-4 appeared to control the ground state conformation of the cyclohexenone core, which determined the diastereoselectivity in the Claisen rearrangement.