With the above promising results in hand, optimization was pursued using a less reactive substrate 3 as shown in Table . In the initial attempt, a diminished yield (29%) was observed due to the higher aromaticity of this compound compared to 1, along with the formation of benzyl alcohol (BnOH) presumably formed via carbonyl reduction. Standard Na or Li-based chemical conditions as well as LER on 3 did not afford any 1,4-diene product 4 (see SI). Instead, various over-reduced products and fragmentation-derived products predominated. A systematic study of chemical and electrochemical parameters revealed that dimethylsulfide (DMS) could be employed as a sacrificial electron-donor to improve the yield (Table , Panel A). Thus, the rest of the optimization was conducted using 3.0 equiv of DMS. Electrodes and electrolytes were found critical to achieve good reactivity (Table , Panel B). In particular, all electrodes examined resulted in little or no conversion with the exception of reticulated vitreous carbon (RVC) and boron-doped diamond (BDD). Due to the inexpensive nature of RVC, it was used exclusively in this study. A screening of electrolytes indicated that tetraalkyl ammonium salts were superior (except for the highly basic Me4N•OH), while employing LiClO4 reduced conversion (Table , Panel C). As demonstrated in our previous rAP study, the electrochemical driving force delivered is a function of both current and frequency (Table , Panel D). Thus, either decreasing pulse width (increasing frequency) or reducing current resulted in decreased conversion. Constant potential rAP (using the same terminal potential observed under constant current with 5 equiv. of Me4N•BF4 as electrolyte) gave a similar product distribution to constant current rAP. Since a slight warming of the reaction was noted (from 23 °C to 35 °C, see SI) submerging the reaction vessel in a 0 °C ice bath further increased the desired product yield to 59% (best yield) by suppressing BnOH formation originated from the carbonyl reduction. The nature of solvent and pH of the reaction (Table , Panel E) also affected the ratio of the arene reduction vs the carbonyl reduction. Lastly, several control experiments under direct current conditions were performed to provide a comparison with the rAP-based method (Table , Panel F). Although a small amount of the desired product was obtained at various current densities, the yield as well as the extent of carbonyl reduction were by no means similar to the rAP-based method. In an effort to mimic the unique reactivity of rAP, constant potential experiments were attempted. Thus, the reaction potential was set to -2.3 V (see SI for cyclic voltammogram of 3) to achieve cleanest reduction possible. Despite this effort, the yield of 4 was still far below the rAP-based method, supportive of the documented fundamental reactivity difference between rAP and DC in other studies. Table . Optimization study. All the reactions were performed on 0.1 mmol scale under the initial conditions with a deviation indicated. Product distribution was analyzed by 1 H NMR. a Reactions were performed with 3 equiv of Me2S. b 1 equiv of electrolyte was used. c 5 equiv of Me4N•BF4 was used. d Indicated additive was added to THF/EtOH (1/1). e Bu4N•BF4 (0.2 M) was used as an electrolyte. • Electrode, electrolyte and current (frequency) affect reactivity.