1: 1.) 2,4,6-triisopropylbenzenesulfonyl chloride, Et3N, pyridine, 2.) sodium azide / 2.) DMF, 100 deg C, 20 h 2: 1.) Ph3P, 2.) H2O / 1.) THF, RT, 20 h 3: sulfonic acid ion-exchange resin / H2O / 1 h 4: H2 / 4percent Pd/C / H2O / 72 h / 3102.9 Torr View Scheme