1: diethyl ether; toluene / 0 °C 2: 80 percent / PhCO2Ag; Et3N / 2 h / Heating 3: LiBH4 / tetrahydrofuran; H2O / 1 h 4: AcOH / 80 °C View Scheme

sodium hydrogencarbonate 4 h; Ambient temperature;