in methanol; hexane suspn. of Fe2(CO)9 and bicyclooctene in hexane/MeOH is stirred at room temp. for 14 h under Ar flux, then at 45°C for 24 h; evapn., taking up in hexane, filtn., addn. of acid alumina to decomposeFe3(CO)12, filtn., evapn., chromy. (silica gel, petroleum ether), recrystn. (hexane, -25°C);

in pentane Irradiation (UV/VIS); Ar-atmosphere; high pressure Hg-lamp (-80°C, 4 h); volume reduction, chromy. (Florisil, hexane); recrystn.;

potassium hydroxide in tetrahydrofuran; dimethyl sulfoxide T=15 - 20°C;

potassium tert-butylate in N,N,N',N',N'',N''-hexamethylphosphoric triamide; N,N-dimethyl-formamide T=80°C; 70 h;

potassium tert-butylate in tetrahydrofuran 70 h; Heating;

1: 88 percent / pyridine / 0 - 3 °C 2: 67 percent / t-BuOK / hexamethylphosphoric acid triamide; dimethylformamide / 70 h / 80 °C View Scheme

1.1: sodium / ethanol / 48 h / Reflux 1.2: 60 h / Reflux 2.1: pyridine; thionyl chloride / 2 h / Reflux 3.1: potassium tert-butylate / tetrahydrofuran / 96 h / 60 °C View Scheme