Synthesis of Some Novel Cyclooctane-Fused-Heterocycles with Anticipated Biological Activities: Cyclooctane-Fused-Heterocycles

Claisen-Schmidt condensation of furan-2-carboxaldehyde 1 with cyclooctanone 2 afforded smoothly the bischalcone: 2,8-bis((furan-2-yl)methylene)cyclooctanone 3. Compound 3 was allowed to react with different organic reagents through 1,2 and 1,4 cycloaddition reactions to afford the cyclooctane-fused heterocyclic compounds 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 and 17a, 17b, 17c in good yields. The structures of all the new compounds were elucidated and deduced from their elemental analyses as well as the spectral data.