Benzofurano derivatives of coumarins as possible antifertility agents

Synthesis and medicinal importance of 4-methyl-6-nitro-8,9,10,11-tetrahydro-2H-benzofuro2,3-b]-1-benzo-pyran-2-one (I), 4-ethyl-11-nitro-6,7,8,9-tetrahydro-2H-benzofuro3,2-g]-1-benzopyran-2-one (II), and 6,7-di-hydro-4,13-dimethylbis-1-benzopyrano6,7-d:7′,6′-d']-2H,11H-benzo1,2-b:3,4-b']difuran-2,11-dione (III) is presented. The structures of these compounds were confirmed by elemental analysis and spectral studies.