1: 93 percent / H2 / Pd/C / methanol / 36 h / 760 Torr 2: 85 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / -78 - -60 °C View Scheme

1: 4-iodo-1,2-methylenedioxybenzene With copper(l) iodide; tetrakis(triphenylphosphine) palladium(0); triethylamine Sonogashira coupling; 0.5 h; 2: propargyl alcohol T=20°C; Sonogashira coupling; 4 h;

dichloro bis(acetonitrile) palladium(II); copper(l) iodide; diisopropylamine; [(t-Bu)3PH]BF4 in 1,4-dioxane T=20°C; Inert atmosphere;

1: 1,1-dibromo-2-(3,4-methylenedioxyphenyl)ethylene With n-butyllithium in tetrahydrofuran T=-78°C; Corey-Fuchs Alkyne Synthesis; 2: formaldehyd in tetrahydrofuran T=-78°C; Corey-Fuchs Alkyne Synthesis;

1.1: triphenylphosphine / dichloromethane / 20 °C 2.1: n-butyllithium / tetrahydrofuran / -78 °C 2.2: -78 °C View Scheme

1: dicyclohexyl-carbodiimide; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 0 - 20 °C 2: acetic anhydride / 140 °C / |Inert atmosphere 3: 2,3-dicyano-5,6-dichloro-p-benzoquinone / benzene / 13 h / 80 °C View Scheme

1.1: tetra(n-butyl)ammonium hydrogensulfate; sodium hydroxide / water / 3 h / 0 °C 2.1: n-butyllithium / tetrahydrofuran; hexane / 1 h / -78 °C 2.2: 0.5 h / -78 °C 3.1: oxalyl dichloride; dimethyl sulfoxide / dichloromethane / 0.25 h / -78 °C 3.2: 0 - 20 °C 4.1: silver hexafluoroantimonate; gold(III) chloride / dichloromethane / 1 h / 20 °C / Molecular sieve 5.1: chromium(VI) oxide; periodic acid / acetonitrile / 1 h View Scheme

hydrogen; palladium on activated charcoal in methanol P=760 Torr; 36 h;

1.1: tetra(n-butyl)ammonium hydrogensulfate; sodium hydroxide / water / 3 h / 0 °C 2.1: n-butyllithium / tetrahydrofuran; hexane / 1 h / -78 °C 2.2: 0.5 h / -78 °C 3.1: oxalyl dichloride; dimethyl sulfoxide / dichloromethane / 0.25 h / -78 °C 3.2: 0 - 20 °C 4.1: silver hexafluoroantimonate; gold(III) chloride / dichloromethane / 0.42 h / 20 °C / Molecular sieve 5.1: chromium(VI) oxide; periodic acid / acetonitrile / 1 h View Scheme