n-butyllithium; chloro-trimethyl-silane; 4-toluenesulfonyl azide; triphenylemethane; diisopropylamine in tetrahydrofuran 1) -78 deg C, 40 min; 2) R.T. 1 h;

1: Et3N / dimethylformamide / 18 h / 0 °C 2: 65 percent / 1) n-BuLi, triphenylmethane, diisopropylamine; 2) p-toluenesulfonyl azide, trimethylsilyl chloride / tetrahydrofuran / 1) -78 deg C, 40 min; 2) R.T. 1 h View Scheme

1: Et3N / dimethylformamide / 18 h / 0 °C 2: 65 percent / 1) n-BuLi, triphenylmethane, diisopropylamine; 2) p-toluenesulfonyl azide, trimethylsilyl chloride / tetrahydrofuran / 1) -78 deg C, 40 min; 2) R.T. 1 h View Scheme

hydrogen fluoride in various solvent(s) 6.5 h;

1: 64 percent / 48percent HF / various solvent(s) / 6.5 h 2: 95 percent / 1) H2; 2) HCO2H / 10percent Pd/C / methanol / 1) 20 min; 2) 1 h, 5 deg C View Scheme