[reaction: see text] Electrochemical oxidation of cyclooctatetraene (COT) in methanol affords a ring-contracted acetal in high yield. Ring contraction is only a minor process in acetic acid. Ab initio computational methods were applied to understand and explain the effect of solvent. The computations show considerable differences between the thermodynamic and kinetic preferences for ring contraction vs bicyclo[4.2.0] product formation.