tetrabutylammomium bromide; hydroxocobalamine hydrochloride in N,N-dimethyl-formamide T=25°C; Cyclization; reduction; elimination; 1.5 h; Electrolysisirradiation with visible light; Title compound not separated from byproducts;

N(Et)4ClO4; NH4Br; Ni(trans-lt;14gt;aneN4)(ClO4)2 in N,N-dimethyl-formamide electroreduction (divided cell, glassy-carbon plate electrode);

tetrabutylammomium bromide; hydroxocobalamine hydrochloride in N,N-dimethyl-formamide T=25°C; Cyclization; reduction; elimination; 1.5 h; Electrolysisirradiation with visible light; Title compound not separated from byproducts;