1: 63 percent / pyridine / 4 h / Ambient temperature 2: 2) NaBH4 / 1) Et2O, 12 h, room temperature, 2) THF, MeOH, -50 deg C, 4 h View Scheme

sodium tetrahydroborate 1) Et2O, 12 h, room temperature, 2) THF, MeOH, -50 deg C, 4 h; Yield given. Multistep reaction. Yields of byproduct given. Title compound not separated from byproducts;