1,1-bis- (3,4-dimethoxyphenyl)alkane was prepared as a precusor of 9-alkyl-fluorene derivatives containing four -OCH₃ groups. 1,1-bis-(3,4-dimethoxyphenyl)alkane was obtained through the intermadiate products of benzophenone derivatives symmetrically substituted by -OCH₃3 which induces electron donor effect and carbinols. The oxidation potential of 1,1-bis-(3,4-dimethoxyphenyl)alkane in CH₃CN(0.1mol Bu₄NBF₄, Pt-electrode, scan rate v=1000mV/s) was 1.31V(vs SCE) and the oxdation and reduction potentials for 9-methyl-2,3,6,7-tetramethoxyfluorene by intramolecular cyclization were 0.74V and 0.68V, respectively