Among the top 200 small molecule drugs by retail sales in 2021, 71 of them contain polycyclic skeletons. The polycyclic structure seems to be ideally suited for developing multiple mechanism drugs, as it can serve both as a scaffold for the drug molecule, or as a moiety that may be added to improve its pharmacokinetic properties. Traditional synthetic strategies towards these structures include multiple-step synthesis and expensive starting materials, which makes them time-consuming, uneconomical, impractical, and sometimes tedious. Hence, it would be highly beneficial if cheap and readily available bulk chemical feedstock - such as the aromatic compounds - could provide direct access to these structures. Traditional chemical reactions applicable for aromatic compounds are restricted by their special stability - aromaticity - and are usually limited to substitution reactions, where the aromaticity of the molecule is preserved. Dearomatization reactions, on the other hand, escape from the restrictions of the inherent two-dimensional structures of aromatic compounds and are able to forge sophisticated three-dimensional molecular topology by disrupting their aromaticity.In this proposal, we aim to take inspiration from known drugs and bioactive natural products, and develop organocatalytic asymmetric dearomatization (OCADA) reactions of aromatic compounds to expand chemical space with novel polycyclic molecular frameworks as possible advanced building blocks in research linked with drug discovery. The main aims of this project are:(i) Development of novel OCADA reactions of aromatic compounds readily available from sustainable sources(ii) Conduction of mechanistic studies in order to elucidate catalyst role and stereochemical induction in developed dearomatization processes(iii) Construction of molecular libraries of polycyclic scaffolds with structural novelty and diversity, and their screening for antitumor and antibacterial activities.