lithium borohydride in tetrahydrofuran T=20°C;

ammonium cerium(IV) nitrate in acetonitrile T=0°C; Oxidation; Oxidative cleavage; 16 h;

silver trifluoroacetate; silica gel in ethyl acetate T=50°C; Wolff rearrangement; 0.25 h;

1.1: ClCOOEt; N-methylmorpholine / tetrahydrofuran / 0.25 h / -15 °C 1.2: tetrahydrofuran; CH2Cl2 / -15 - 20 °C 2.1: CF3COOAg / dioxane; H2O / 0.5 h / sonication View Scheme

1.1: LDA / tetrahydrofuran / 1 h / -78 °C 1.2: 82 percent / tetrahydrofuran / 0.25 h / -78 °C 2.1: 86 percent / aq. (NH4)2Ce(NO3)6 / acetonitrile / 16 h / 0 °C View Scheme

1: 1.) Et3N, EtOCOCl, 2.) NaBH4 / 1.) THF, 0 deg C, 0.25 h, 2.) H2O, 0 deg C, 0.5 h, room temperature, 2 h 2: Et3N, DMAP / CH2Cl2 / Ambient temperature 3: dimethylformamide / 24 h / Ambient temperature 4: 6 M HCl / 12 h / Heating 5: aq. NaOH / 1.) 0 deg C, 0.5 h, 2.) room temperature, 2 h View Scheme

1: 94 percent / aq. sodium hydroxide / 1.) 0 deg C, 0.5 h, 2.) room temperature, 2 h 2: 1.) Et3N, EtOCOCl, 2.) NaBH4 / 1.) THF, 0 deg C, 0.25 h, 2.) H2O, 0 deg C, 0.5 h, room temperature, 2 h 3: Et3N, DMAP / CH2Cl2 / Ambient temperature 4: dimethylformamide / 24 h / Ambient temperature 5: 6 M HCl / 12 h / Heating 6: aq. NaOH / 1.) 0 deg C, 0.5 h, 2.) room temperature, 2 h View Scheme

1: Et3N, DMAP / CH2Cl2 / Ambient temperature 2: dimethylformamide / 24 h / Ambient temperature 3: 6 M HCl / 12 h / Heating 4: aq. NaOH / 1.) 0 deg C, 0.5 h, 2.) room temperature, 2 h View Scheme

1: dimethylformamide / 24 h / Ambient temperature 2: 6 M HCl / 12 h / Heating 3: aq. NaOH / 1.) 0 deg C, 0.5 h, 2.) room temperature, 2 h View Scheme

1.1: thionyl chloride / 1 h / -20 °C 1.2: 25 °C 2.1: triethylamine / tetrahydrofuran / 0.5 h 2.2: 3 h / 20 °C 3.1: lithium borohydride / tetrahydrofuran / 20 °C View Scheme