sodium tetrahydroborate in acetone 1.5 h; Ambient temperature;

1: dimethylsulfoxide; dimethylformamide / 24 h 2: TFA, anisole View Scheme

1H-imidazole; polymer-bound 4-hydroxy-3-nitrobenzophenone,DCC; triethylamine; N-ethyl-N,N-diisopropylamine; dicyclohexyl-carbodiimide 1.) CH2Cl2, THF, 1 H, 25 deg C, -10 -0 deg C,10 h; 2.) 0 deg C, CH2Cl2, 24 h; Yield given. Multistep reaction;

1: 87 percent / NaBH4 / acetone / Ambient temperature 2: 81 percent / NaBH4 / acetone / 1.5 h / Ambient temperature View Scheme

1: 87 percent / NaBH4 / acetone / Ambient temperature 2: 81 percent / NaBH4 / acetone / 1.5 h / Ambient temperature View Scheme

1: TFA, anisole 2: dimethylsulfoxide; dimethylformamide / 24 h 3: TFA, anisole View Scheme