1: 89 percent / benzenesulfonyl chloride, pyridine / 0 °C 2: 41 percent / LDA / tetrahydrofuran; hexane / 0.33 h / -78 °C 3: H2 / 10percent Pd-C / ethyl acetate View Scheme

1: 89 percent / benzenesulfonyl chloride, pyridine / 0 °C 2: 41 percent / LDA / tetrahydrofuran; hexane / 0.33 h / -78 °C 3: H2 / 10percent Pd-C / ethyl acetate 4: 85.8 percent / PPh3, diethyl azodicarboxylate / tetrahydrofuran / Ambient temperature View Scheme

1: 89 percent / benzenesulfonyl chloride, pyridine / 0 °C 2: 41 percent / LDA / tetrahydrofuran; hexane / 0.33 h / -78 °C 3: H2 / 10percent Pd-C / ethyl acetate View Scheme