1: 2-(4-bromophenyl)-1,3,4-oxadiazole With methyllithium in tetrahydrofuran; formaldehyde diethyl acetal T=-65°C; 1 h; 2: With n-butyllithium in tetrahydrofuran; hexanes; formaldehyde diethyl acetal T=-65°C; 1 h; 3: tri-isopropoxy-borane With acetic acid more than 3 stages;

1: With p-tolyl-lithium in tetrahydrofuran T=-65°C; 0.5 h; 2: With n-hexyl lithium in tetrahydrofuran; hexanes T=-65°C; 0.5 h; 3: With tri-isopropoxy-borane; water; acetic acid Product distribution / selectivity; more than 3 stages;