Abstract:In the present study, a series of 1,3-diaryl-1,3,3a,8a-tetrahydro-8H-spiro[cyclopenta[a]indene-2,2'-indene]-1',8(3'H)-dione derivatives (4a-h) were synthesized by KOt-Bu catalyzed dimerization of 2-benzylidene inden-1-one derivatives. The structures of obtained novel spiro-dimeric compounds were characterized using the spectroscopic methods ( 1 H, 13 C, 2D NMR and IR).