potassium carbonate in acetone 48 h; Heating;

potassium tert-butylate in 2-methoxy-ethanol; N,N-dimethyl-formamide

hydrogenchloride; sodium hydroxide in water; ethyl acetate; acetone

ethanol T=150°C;

hydrogen; Ra-Ni in methanol T=40°C; P=36775.4 Torr; 2 h;

1: in tetrahydrofuran T=-5°C; 0.5 h; 2: With 2,3-dicyano-5,6-dichloro-p-benzoquinone in tetrahydrofuran T=20°C; 2 h;

1.1: tetrahydrofuran / 0.5 h / -5 °C 1.2: 81 percent / DDQ / tetrahydrofuran / 2 h / 20 °C 2.1: 85 percent / TBAF; isopropyl acetate / tetrahydrofuran / 20 °C 3.1: 87 percent / isopropyl acetate / tetrahydrofuran / 1 h / 20 °C 4.1: 4.55 g / DBU; isopropyl acetate / 1 h / 70 °C 5.1: 94 percent / PPh3; CO / Pd(OAc)2 / acetonitrile / 12 h / 70 °C / 4560 Torr View Scheme