1: 92 percent / pTsOH / toluene / 8 h / Heating 2: 24 percent / H2O / 5 h / 150 °C 3: 55 percent / diethyl azodicarboxylate, Ph3P / tetrahydrofuran / 18 h / Ambient temperature 4: 56 percent / piperidine / ethanol / 18 h / Heating 5: 96 percent / NaBH4, 1.0N aq. NaOH, CoCl2*6H2O, dimethylglyoxime / dimethylformamide; tetrahydrofuran / 18 h / Ambient temperature View Scheme

1: NaH / dimethylformamide; toluene / 2.5 h / 80 °C 2: 10percent aq. H2SO4 / 2 h / Heating 3: 92 percent / pTsOH / toluene / 8 h / Heating 4: 24 percent / H2O / 5 h / 150 °C 5: 55 percent / diethyl azodicarboxylate, Ph3P / tetrahydrofuran / 18 h / Ambient temperature 6: 56 percent / piperidine / ethanol / 18 h / Heating 7: 96 percent / NaBH4, 1.0N aq. NaOH, CoCl2*6H2O, dimethylglyoxime / dimethylformamide; tetrahydrofuran / 18 h / Ambient temperature View Scheme

1: 10percent aq. H2SO4 / 2 h / Heating 2: 92 percent / pTsOH / toluene / 8 h / Heating 3: 24 percent / H2O / 5 h / 150 °C 4: 55 percent / diethyl azodicarboxylate, Ph3P / tetrahydrofuran / 18 h / Ambient temperature 5: 56 percent / piperidine / ethanol / 18 h / Heating 6: 96 percent / NaBH4, 1.0N aq. NaOH, CoCl2*6H2O, dimethylglyoxime / dimethylformamide; tetrahydrofuran / 18 h / Ambient temperature View Scheme

1: 24 percent / H2O / 5 h / 150 °C 2: 55 percent / diethyl azodicarboxylate, Ph3P / tetrahydrofuran / 18 h / Ambient temperature 3: 56 percent / piperidine / ethanol / 18 h / Heating 4: 96 percent / NaBH4, 1.0N aq. NaOH, CoCl2*6H2O, dimethylglyoxime / dimethylformamide; tetrahydrofuran / 18 h / Ambient temperature View Scheme

1: 55 percent / diethyl azodicarboxylate, Ph3P / tetrahydrofuran / 18 h / Ambient temperature 2: 56 percent / piperidine / ethanol / 18 h / Heating 3: 96 percent / NaBH4, 1.0N aq. NaOH, CoCl2*6H2O, dimethylglyoxime / dimethylformamide; tetrahydrofuran / 18 h / Ambient temperature View Scheme

1: 56 percent / piperidine / ethanol / 18 h / Heating 2: 96 percent / NaBH4, 1.0N aq. NaOH, CoCl2*6H2O, dimethylglyoxime / dimethylformamide; tetrahydrofuran / 18 h / Ambient temperature View Scheme