Quartromicins; Enantioselective Total Synthesis and Generating Molecular Libraries of Drug-like Bioactive Compounds.

2026-07-22

Nature is an indispensable source of bioactive compounds, but not necessarily an ideal provider of bulk or analogs. Total synthesis plays an important role in generating new analogs of natural molecules and as a means to reduce dependency on natural resources. The outbreak of COVID-19 and other viruses has posed a significant global threat, the urgent need arises to study and discover new antiviral. It has become imperative for researchers to develop strategic research plans in order to synthesize medicines to combat these viruses. Quartromicins are well known for their antiviral properties but barely explored due to no known synthesis to date and low isolation yield (0.36-0.06%) makes them an attractive target molecule for the total synthesis for further investigation and development to combat the viruses. With this proposal, we address the synthetic aspects of the main bioactive molecules and their analogs being considered to be repositioned for the effective treatment of viral infections. The first total synthesis of Quartromicins A1, A2, A3, D1, D2, D3 is proposed by a convergent synthetic strategy that involves the use of an enantioselective Diels-Alder reaction, the carbonyl-ene reaction mediated by organocatalyst, and the Heck dimerizing coupling reaction as the key step to the macrocyclization. The endo adduct is proposed to be readily synthesized by the enantioselective Diels-Alder reaction while the exo unit by a carbonyl-ene reaction, both mediated by the organocatalyst. The exo & endo fragments are proposed to be transformed to the corresponding exo & endo-spirotetronate fragments by simple organic transformations. Finally, the symmetrical Quartromicins A1, A3, D1 & D3 and unsymmetrical Quartromicins A2 & D2 can be synthesized by the Heck dimerizing coupling and the Heck double cross-coupling reactions respectively. The late-stage glycosylation strategy shall furnish a library of bioactive molecules essential for medicinal chemistry applications.

France

2025-12-01