The canonical Birch reduction is typically applicable to only a limited number of heterocycles. The lack of chemoselectivity of the process is evident in the absence of a literature precedent for reduction of a trivial heterocycle methyl 2-thiophenecarboxylate 1 (Figure ). This is understandable since Birch reduction of thiophenecarboxylic acid poses an issue of ring fragmentation. The ester functionality could cause more chemoselectivity issues such as overreduction or further facilitating C-S bond cleavage. Accordingly, the reduction product 2 was previously accessed by careful Birch reduction of thiophene-2-carboxylate Li salt, followed by mild esterification. Intrigued by the absence of such an example, several representative Birch reduction conditions were applied on this simple substrate 1 (Figure ). Not surprisingly, standard Birch conditions 5 (entry 1) resulted in complete decomposition of the starting material. The most recent modification (entry 2) showed attenuated reactivity, yet extensive decomposition was still observed. Donohoe's LiDBB method (entry 3) afforded the product in 39% yield, which is reasonable considering that this method is particularly suitable for electron-deficient heterocycles. Yet, concerns remain; LiDBB is highly sensitive (necessitating stringent degassing) and removal of large amount of DBB is problematic. Additionally, in this particular case the cost of DBB ($915/mol, TCI) surpasses the cost of the starting material itself ($571/mol, TCI). Turning to electrochemical conditions, LER 10 (entry 4) also led to decomposition. Although simple electrolysis of 1 under DC current in THF/EtOH with RVC electrodes resulted in decomposition (entry 5), it actually showed some peaks in the crude NMR indicative of trace dearomatization products. In striking contrast, under otherwise identical conditions, simply changing the waveform to rapid alternating polarity (rAP, entry 6) afforded 83% of the desired product (crude NMR shown in Figure ).