Abstract The 1,2,6,7-tetraphenyl-4-oxa-spiro[2.4]hepta-1,6-dien-5-one (spirolactone, 1 ) has been prepared and investigated with reference to its redox properties, using cyclic voltammetry and controlled potential electrolysis in dimethylformamide (DMF) using Et 4 NClO 4 as supporting electrolyte. The most relevant features are the three reduction steps, E p 1 =−1.68 V, E p 2 =−2.34 V, E p 3 =−2.62 V (SCE) which are irreversible on the time scale of the voltammetric experiments used. The first electron/molecule transfer, with no corresponding anodic process, gives rise to an unstable radical anion, which, by rupture of the three-membered ring at the spiro carbon, rearranges to a distonic radical anion. The presence of 5-(1,2-diphenyl-vinyl)-3-(5-hydroxy-1,2,6,7-tetraphenyl-4-oxa-spiro[2.4]hepta-1,6-dien-5-yl)-3,4-diphenyl-3 H -furan-2-one ( 5 ) (40%) among the isolated products, after controlled potential electrolysis, points to a further attack of the distonic radical anionic species on the starting compound 1 . Thus, the dimeric unsymmetric lactone 5 retains the spiro structure in one half of the molecule.