1.1: triphenylemethane; n-butyllithium / tetrahydrofuran; hexane / 1 h / -78 °C 1.2: 2.5 h / -78 - 20 °C 2.1: sodium hexamethyldisilazane / tetrahydrofuran / 1.17 h / -78 °C 2.2: 8.5 h / -78 - -45 °C 3.1: Grubb's 2nd generation catalyst / dichloromethane / 27 h / |Reflux 4.1: osmium(VIII) oxide; 4-methylmorpholine N-oxide / water; acetone / 21 h / 20 °C 5.1: tert.-butyl lithium / tetrahydrofuran; pentane / 1.83 h / -78 °C 5.2: 19 h / -78 °C 6.1: hydrogen; palladium on activated charcoal / methanol / 67 h / 2947.82 Torr 7.1: triethylamine / dichloromethane / 2 h / -10 - 0 °C 8.1: lithium bromide / tetrahydrofuran / 23 h / |Reflux 9.1: sodium azide / N,N-dimethyl-formamide / 48 h / 90 °C View Scheme

1: malonic acid ethyl ester monopotassium salt With triethylamine; magnesium chloride in acetonitrile T=10 - 25°C; 2.5 h; 2: 3-methyl-butyryl chloride With triethylamine in acetonitrile T=0 - 25°C; 18 h;

1: ethyl acetate With n-butyllithium; diisopropylamine in tetrahydrofuran; hexane T=-70°C; 0.5 h; 2: 3-methyl-butyryl chloride in tetrahydrofuran; hexane T=-70°C; 0.666667 h;

1: 2,2-Dimethyl-[1,3]dioxane-4,6-dione; 3-methyl-butyryl chloride With pyridine in dichloromethane T=0 - 20°C; 2: ethanol 4 h; Heating;

1: pyridine / CH2Cl2 / 2 h / 0 - 20 °C 2: toluene / Heating View Scheme

(i) Mg, Et2O, EtOH, (ii) aq. H2SO4, (iii) aq. NH3; Multistep reaction;

1: 83 percent / Et3N 2: 73 percent / tetrahydrofuran / 0.5 h / Ambient temperature View Scheme

1: 1.) Et3N, 2.) 20percent aq. HCl / 1.) CHCl3, room temp., 15 h, 2.) reflux, 5 h 2: aq. NaOH / 1 h / Heating 3: 93 percent / KOH, N2H4*H2O / bis-(2-hydroxy-ethyl) ether / 23 h / Heating 4: 90 percent / 1.) SOCl2 / 1.) room temp., 3 h, 2.) reflux, 2 h 5: diethyl ether / 1.) room temp., overnight, 2.) reflux, 3 h View Scheme

chloroform; triethylamine; toluene anschliessendes Behandeln mit L-Phenylalanin-aethylester und Behandeln des Reaktionsprodukts mit wss. NaOH;

in benzene Heating;