A VO(acaC)(2)/[VO(acac)(2)OOH](-) redox mediator was used for the cathodic oxidation of olefinic compounds to the corresponding epoxides. The oxidation process consists of a multi-step such as (a) cathodic reduction of dioxygen to hydrogen peroxide, (b) chemical oxidation of VO(acac)(2) to [VO(acac)(2)OOH](-) with the resulting hydrogen peroxide, (c) the chemical epoxidation of olefins with [VO(acac)(2)OOH](-), and (d) the regeneration of VO(acac)(2). On the other hand, the olefinic compounds are indirectly oxidized (brominated) with a Br-/Br+ mediator to give the corresponding 1,2-dibromides. Pairing this indirect anodic oxidation (bromination) with the above indirect cathodic epoxidation, an efficient paired electrosynthetic system could be developed for preparation of epoxides and 1,2-dibromides. (C) 2003 Elsevier Science Ltd. All rights reserved.