N-ethyl-N,N-diisopropylamine in acetonitrile T=20 - 60°C; 18 h;

potassium carbonate in N,N-dimethyl-formamide T=50°C; 2 h;

potassium hexamethylsilazane in tetrahydrofuran; toluene T=0 - 20°C;

1: potassium carbonate / N,N-dimethyl-formamide / 80 °C 2: potassium carbonate / dimethyl sulfoxide / 3 h / 90 °C View Scheme

ethanol

T=180°C; 6 h;

1.1: tetrahydrofuran; diethyl ether / 0.5 h / -5 °C 1.2: 84 percent / aq. I2 / tetrahydrofuran; diethyl ether / 2 h / 20 °C 2.1: TBAF; isopropyl acetate / tetrahydrofuran / 0.5 h / 20 °C 3.1: isopropyl acetate / tetrahydrofuran / 1 h / 20 °C 4.1: 7.09 g / DBU; isopropyl acetate / 1 h / 70 °C 5.1: 88 percent / PPh3; CO / Pd(OAc)2 / acetonitrile / 12 h / 70 °C / 4560 Torr View Scheme

hydrogen; palladium 10 on activated carbon in ethanol P=2068.65 Torr; 0.5 h;