Several polycyclic natural products with a coumarinic moiety display a large number of biological properties (anti-bacterial, 1., and anti-tumoral, 2 anti-HIV 3., , , and …). Due to those varied biological activities, a considerable amount of synthetic work in the field of coumarins with [3,4]-carbocyclic or [3,4]-heterocyclic fused ring systems has been done 4 . Classical reactions (such as Pechmann condensation, Michaël addition…) are still used but the development of ...
