1: 1 N KOH / ethanol / 4 h / 50 °C 2: benzenesulfonyl chloride, pyridine / 0 °C 3: H2 / 10percent Pd-C / ethyl acetate View Scheme

1: 1 N KOH / ethanol / 4 h / 50 °C 2: benzenesulfonyl chloride, pyridine / 0 °C 3: H2 / 10percent Pd-C / ethyl acetate 4: 85.8 percent / PPh3, diethyl azodicarboxylate / tetrahydrofuran / Ambient temperature View Scheme

1: 1 N KOH / ethanol / 4 h / 50 °C 2: benzenesulfonyl chloride, pyridine / 0 °C 3: H2 / 10percent Pd-C / ethyl acetate View Scheme