trifluoroacetic acid in tetrahydrofuran; water T=60 - 65°C; 2 h;

hydrogen; palladium on activated charcoal in ethyl acetate Catalytic hydrogenation; 6 h;

1: 1) BH3, 2) pyridinium chlorochromate / 1) THF, 0 deg C, 30 min, 2) CH2Cl2, reflux, 2 h 2: 1) NaOMe / 1) DMSO, r.t., 15 min, 2) r.t., 1 day 3: 68 percent / H2 / 5percent Pd-C / methanol / 2280 Torr 4: 84 percent / CF3COOH / tetrahydrofuran; H2O / 2 h / 60 - 65 °C View Scheme

1: 1) NaOMe / 1) DMSO, r.t., 15 min, 2) r.t., 1 day 2: 68 percent / H2 / 5percent Pd-C / methanol / 2280 Torr 3: 84 percent / CF3COOH / tetrahydrofuran; H2O / 2 h / 60 - 65 °C View Scheme

1: 75 percent / DBU / tetrahydrofuran / 8 h 2: 100 percent / H2 / Pd/C / ethyl acetate / 6 h View Scheme

1: 75 percent / DBU / tetrahydrofuran / 8 h 2: 100 percent / H2 / Pd/C / ethyl acetate / 6 h View Scheme