1: carbon dioxide; buta-1,3-diene With tetra-n-butylammonium perchlorate; hydrogen; triethylamine in N,N-dimethyl-formamide T=20°C; Carboxylation; P=7.35558 Torr; 6 h; Electrochemical reaction; 2: diazomethane in diethyl ether Methylation;

(1,10-phenanthroline)Ni(1,5-cyclooctadiene) 1.) THF, -10 deg C, 2 h, 2.) ether, reflux, 8 h; Multistep reaction;