1: 24 percent / NaBH4 / ethanol / 16 h / 40 °C 2: 98 percent / 2 N KOH / methanol / 50 °C View Scheme

1: 77 percent / dimethylsulfoxide / 70 °C 2: 88 percent / HCl / 12 h / 4 °C 3: 24 percent / NaBH4 / ethanol / 16 h / 40 °C 4: 98 percent / 2 N KOH / methanol / 50 °C View Scheme

1: 94 percent / Na2Cr2O7, conc. H2SO4 / diethyl ether; H2O / 25 °C 2: 88 percent / HCl / 12 h / 4 °C 3: 24 percent / NaBH4 / ethanol / 16 h / 40 °C 4: 98 percent / 2 N KOH / methanol / 50 °C View Scheme

1: 1) NaH, 2) conc. HBr / 1) DMF, 1 h, 70 deg C, 2) 15 h, reflux 2: 34 percent / 2 N NaOH, NaBH4 / ethanol / 16 h / 50 °C / EtOH, Na View Scheme

sodium tetrahydroborate Yield given. Yields of byproduct given;

1: 67 percent / Na2Cr2O7, conc. H2SO4 / diethyl ether / 2 h / Ambient temperature 2: 55 percent / 2 N NaOH, NaBH4 / ethanol / 16 h / 50 °C / EtOH, Na 3: 98 percent / 20percent diisobutyl aluminium hydride / toluene; hexane / 2 h / -40 °C 4: 99 percent / p-toluenesulfonic acid, molecular sieve 4 Angstroem / diethyl ether; petroleum ether / 1 h / Ambient temperature 5: 80 percent / HCl / diethyl ether View Scheme