The problem, using modern computational techniques to solve the diffusion-kinetic task, can be resolved by carrying out preparative electrolysis on rotating disc electrodes RDE, or rotating ring electrodes Frumkin and Nekrasov (RRDE) ; the theoretical basis was developed in detail by Levich (cf. book ). The special advantages here are: Stationary laminar mass transfer mode with controlled hydrodynamics; additional opportunity to vary the length of reaction layer; in situ electroanalytical control during electrolysis (the RRDEcase); increased current density/electrolysis performance; good opportunities for a theoretical description of process on RDE/RRDE. The mathematical solution, including the ee v de v p transformation, scheme 3, was obtained by the NAMBE (for details see ). Convenient formulas derived in this way, applicable to various HOMEC cases , were used in the kinetic analysis of the electroreduction of pentadienol and its derivatives (scheme 3).