Isolation and Biomimetic Semisynthesis of Hyperzrones A and B, Two Nor-Polycyclic Polyprenylated Acylphloroglucinols with a Characteristic Cyclobutane Moiety, from Hypericum beanii

Hyperzrones A ( 1 ) and B ( 2 ), two unprecedented nor -polycyclic polyprenylated acylphloroglucinols with a characteristic cyclobutane moiety, were discovered from Hypericum beanii . Their structures were determined by extensive spectroscopic analysis, X-ray crystallography, and quantum chemical calculation methods. A bioinspired semisynthesis of 1 and 2 was achieved from the natural precursor hypercalin B ( 3 ), featuring a Favorskii-type rearrangement and a visible-light-mediated [2 + 2] photocycloaddition. Several diverse derivatives were also obtained, providing a compound library for biological studies.