1: S-tert-Butyl thioacetoacetate With sodium hydride in ethylene glycol dimethyl ether T=-40°C; deprotonation; 0.25 h; 2: With n-butyllithium in ethylene glycol dimethyl ether; 1,1,2,3,4,4-hexachloro-1,3-butadiene T=-40 - -20°C; deprotonation; 3: ethyl bromide in ethylene glycol dimethyl ether; hexane T=-40 - 0°C; Alkylation;

n-butyllithium; sodium hydride in ethylene glycol dimethyl ether; hexane 1.) 0 deg C, 10 min; -20 deg C, 10 min; 2.) 0 deg C;

n-butyllithium; sodium hydride 1.) dimethoxyethane, 0 deg C, 5 min; -30 deg C, dimethoxyethane, hexane, 10 min; 2.) r.t., 1 h , dimethoxyethane;

1.1: 62 percent / NaH / 1,2-dimethoxy-ethane / 14 h / 20 °C 2.1: 49 percent / AgOCOCF3 / 1,2-dimethoxy-ethane / 15 h / 20 °C 3.1: 100 percent / aq. H2SO4 / 3 h / 20 °C 4.1: 87 percent / CAN / acetonitrile; H2O / 3 h / 20 °C 5.1: 14 percent / silica gel / CHCl3 / 0.02 h / 20 °C 6.1: UHP / trifluoroacetic acid / 4 h / 20 °C 6.2: 30 percent / TsCl / acetonitrile; H2O / 4 h / 60 °C View Scheme