dimethyl acetylenedicarboxylate in toluene under Ar, Fe complex, MeO2CC2CO2Me, and PhC2Ph heated at 105°C in toluene for 15 h; evapd., chromd. (SiO2, hexane-toluene); elem. anal.;

in toluene (Ar) an excess of acetylene-compounds were added to the soln. of complexin toluene, the mixt. was heated under Ar at 70.degre.C overnight; the solvent was removed, silica chromy., hexane-CH2Cl2 (40:3);

in toluene react. Fe2(CO)9 with 1,2,3-triphenylphosphirene in toluene at 50°C for 45 min;