in dimethyl sulfoxide 13 h; Heating;

diisobutylaluminium hydride in dichloromethane; toluene T=-70°C; 1 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

1: 100 percent Chromat. / HgO, Na2EDTA / ethanol; H2O / 1 h / 80 °C 2: 86 percent / dimethylsulfoxide / 13 h / Heating View Scheme