1: isothiocyanatomethane With n-butyllithium; potassium tert-butylate; diisopropylamine in tetrahydrofuran; hexane T=-100 - -20°C; Metallation; 2: in tetrahydrofuran; hexane; dimethyl sulfoxide T=40°C; Cycloaddition; 0.291667 h; 3: methyl iodide in tetrahydrofuran; hexane; dimethyl sulfoxide T=-10 - 40°C; Methylation; 0.25 h;

in tetrahydrofuran; hexane; water T=50°C; Methylation; 0.5 h;

water; lithium diisopropyl amide 1.) hexane, THF, -95 deg C, 10 min; 2.) 20 deg C, 1 h; 3.) 50 deg C, 15 min; Yield given. Multistep reaction;

n-butyllithium 1.) Et2O, reflux, 6 h, 2.) -78 deg C, 5 min; room temperature, 17 h; Yield given. Multistep reaction. Yields of byproduct given;