Synthesis and crystal structure analysis of substituted bi-cyclo-[3.3.1]nona-nones

Abstract

Polycyclic polyprenylated acylphloroglucinols (PPAPs) are a class of structurally complex natural products predominantly isolated from plants of the Hypericum and Garcinia genera. Characterized by a highly oxygenated polycyclic core densely decorated with various substituents, these compounds exhibit remarkable chemical diversity and biological activity (Yang et al., 2018). Notably, a single representative can already cover a wide range of different activities. The most important of these may include anti-inflammatory, antibacterial and antiviral activity, as well as cytotoxicity, antitumour properties and use as an antidepressant and neuroprotective agent. Hyperforin, the most prominent and best-studied PPAP to date, may serve as an example of the latter point in particular (Richard, 2014). The pronounced bicyclic framework, common to most PPAPs and many other natural compounds (Roy et al., 2023), makes them particularly compelling for research in natural product chemistry and medicinal applications.