카본 전극을 이용한 양극산화을 통해 1,1-Bis-(3,4-dimethoxyphenyl)ethane으로부터 CH₃CN이나 CH₂Cl₂/TFA-혼합용액계에서 Intramolecular cyclization 반응이 일어났다. Intramolecular cyclization에 의한 생성물(9-methyl-2,3,6,7-tetramethoxyfluorene)은 출발물질보다 더 쉽게 산화되고, 그에 따른 산화생성물은 CH₃CN계에서 불안정하여 낮을수율을 나타냈다. TFA가 존재하는 계에서는 Fluorene 유도체의 산화생성물인 radical cation이 안정하여 환원 후에 더 좋은 수율로 합성할 수 있었다.

The intramolecular cyclizaticn of 1,1-bis-(3,4-dimethoxyphenyl)ethane was shown to take place upon anodic oxidation at carbon electrodes in acetonitrile or in a solvent-mixture containing dichloromethane, trifluoroacetic acid(TFA). Yields are low in the former solvent due to the fact that the cyclized product (9-methyl-2,3,6,7-tetramethoxyfluorene) is more easily oxidized than it`s precursor and the oxidation product is not stable. In the presence of TFA, the cation radical derived from the oxidation of the cyclized product is stabilized thus, after reduction may be isolated with better yields.