1: With magnesium; triethylamine; benzo[1,3,2]dioxaborole in tetrahydrofuran T=65°C; 40 h; 2: With hydrogenchloride in water pH=1;

tri-isopropoxy-borane; lithium bis((trifluoromethyl)sulfonyl)amide in N,N-dimethyl-formamide T=20°C; Electrochemical reaction;