sodium hydride

1: 2.) H3O(1+) 2: 58 percent / NaH View Scheme

1: 92 percent / NaBH4 2: 78 percent / NaH / tetrahydrofuran 3: 47 percent / 5percent Pd<P(OiPr)3>4 / tetrahydrofuran; dimethylsulfoxide 4: 84 percent / 0.5 N NaOH / 2 h / Heating View Scheme