Coumarin and its annulated heterocycles are mainly found in natural products, many of that showed significant biological activities and widely used for the preparation of drug molecules. Investigation revealed that many heterocyclic compounds fused with coumarin moiety exhibited antihelmentic, hypnotic, insecticidal, antifungal and anti-coagulant properties. In industry, coumarin scaffolds are widely used for the preparation of pharmaceuticals, agrochemicals, pesticides and dye molecules. In recent studies, several coumarin derivatives have been used in the material science for the preparation of organic cell imaging materials, fluorescent biological probes etc. Due to the immense applications in biological science and materials chemistry field, much attention has been paid by the researchers towards the synthesis of new class of coumarin annulated heterocycles. In this paper, the synthesis of coumarin-annulated polycyclic heterocycles via sequential Claisen rearrangement and tin-hydride mediated radical cyclization has been discussed. The requisite starting materials 3-((4-chlorobut-2-yn-1-yl)oxy)-2H-chromen-2-one (1) was prepared from 3-hydroxycoumarin and 1,4-dichlorobut-2-yne. The Claisen rearrangement of 1 in refluxing chlorobenzene afforded 1-(chloromethyl)pyrano[2,3-c]chromen-5(3H)-one (2). Finally, radical cyclization reactions were carried out smoothly using ⁿBu₃SnH and AIBN in toluene at 110 ^oC, leading to the coumarin-annulated polycyclic heterocycles in high yields. The process is operationally simple and easy to work-up that makes it more convenient for the preparation of coumarin annulated heterocycles.