1: NEt3 / tetrahydrofuran / 0.75 h / -10 °C 2: 59 percent / tetrahydrofuran / Ambient temperature 3: 49 percent / NaBH4, acetic acid / tetrahydrofuran / 3.5 h / Heating 4: 61 percent / PPh3, n-Bu3N / Pd(OAc)2 / hexamethylphosphoric acid triamide / 5 h / 100 °C View Scheme

1: NEt3 / tetrahydrofuran / 0.75 h / -10 °C 2: NaBH4, H2O / tetrahydrofuran / 1.) 0 deg C, 50 min.; 2.) room temp., 50 min. View Scheme

1: NEt3 / tetrahydrofuran / 0.75 h / -10 °C 2: 59 percent / tetrahydrofuran / Ambient temperature 3: 49 percent / NaBH4, acetic acid / tetrahydrofuran / 3.5 h / Heating 4: 61 percent / PPh3, n-Bu3N / Pd(OAc)2 / hexamethylphosphoric acid triamide / 5 h / 100 °C 5: 90 percent / H2 / PtO2 / ethanol View Scheme