1: 86 percent / Et3N / dimethylformamide / 1 h / Ambient temperature 2: 2.) n-Bu4NF / 1.) CH2Cl2, room remperature, 2 h, 2.) MeCN, THF, 0 deg C, 1 h View Scheme

sodium tetrahydroborate 1.) MeCN, room remperature, 1 h, 2.) Et2O, CH2Cl2, room temperature, 30 min; Multistep reaction. Title compound not separated from byproducts;

tetrabutyl ammonium fluoride 1.) CH2Cl2, room remperature, 2 h, 2.) MeCN, THF, 0 deg C, 1 h; Multistep reaction. Title compound not separated from byproducts;