pyridine; oxygen; sodium carbonate; palladium (II) trifluoroacetate; 3 A molecular sieve in toluene T=80°C; Wacker cyclization; P=760 Torr; 25 h;

1.1: t-BuLi / tetrahydrofuran; pentane / 1.5 h / -78 °C 1.2: 47 percent / tetrahydrofuran; pentane / 1 h / -78 °C 2.1: 93 percent / pyridine; Na2CO3; molecular sieves 3 Angstroem / Pd(TFA)2; O2 / toluene / 25 h / 80 °C / 760 Torr View Scheme

1.1: NaH / benzene / 0 °C 1.2: 49 percent / benzene / 24 h / 23 °C 2.1: t-BuLi / tetrahydrofuran; pentane / 1.5 h / -78 °C 2.2: 47 percent / tetrahydrofuran; pentane / 1 h / -78 °C 3.1: 93 percent / pyridine; Na2CO3; molecular sieves 3 Angstroem / Pd(TFA)2; O2 / toluene / 25 h / 80 °C / 760 Torr View Scheme

1.1: NaH / benzene / 0 °C 1.2: 49 percent / benzene / 24 h / 23 °C 2.1: t-BuLi / tetrahydrofuran; pentane / 1.5 h / -78 °C 2.2: 47 percent / tetrahydrofuran; pentane / 1 h / -78 °C 3.1: 93 percent / pyridine; Na2CO3; molecular sieves 3 Angstroem / Pd(TFA)2; O2 / toluene / 25 h / 80 °C / 760 Torr View Scheme

tetrabutyl-ammonium chloride; sodium acetate; bis(dibenzylideneacetone)-palladium(0) in N,N-dimethyl-formamide T=100°C; 24 h; Yield given. Yields of byproduct given;