1.1: t-BuOK / tetrahydrofuran / 0.5 h / 20 °C 1.2: 93 percent / Pd(PPh3)4 / tetrahydrofuran / 3 h / 50 °C 2.1: 89 percent / KI / H2O; various solvent(s) / 10 h / 130 °C 3.1: 89 percent / (i-Bu)2AlH / CH2Cl2; hexane / 0.75 h / -78 °C 4.1: NaN(TMS)2 / tetrahydrofuran / 0.5 h / 20 °C 4.2: 84 percent / tetrahydrofuran / -70 - 20 °C 5.1: 95 percent / TBAF / tetrahydrofuran / 5 h / 20 °C 6.1: 93 percent / PCC / CH2Cl2 / 3 h / 20 °C 7.1: LDA / tetrahydrofuran; hexane / 0.33 h / -78 °C 7.2: tetrahydrofuran; hexane / 0.33 h / -78 °C 7.3: Et3N / CH2Cl2 8.1: 92 percent / DDQ / CH2Cl2; H2O / 0.75 h / cooling 9.1: 92 percent / PCC / CH2Cl2 / 2.5 h / 20 °C 10.1: 93 percent / 2-methyl-2-butene; NaClO2 / 2-methyl-propan-2-ol; H2O; various solvent(s) / 3 h / 20 °C View Scheme

tetrabutyl ammonium fluoride

1.1: 90 percent / NaOMe; MeOH / 24 h / 20 °C 2.1: DMAP / dimethylformamide / 20 h / 100 °C 3.1: tetrabutylammonium fluoride / tetrahydrofuran / 2 h / 20 °C 4.1: 84 percent / diisopropylethylamine; methanesulfonyl chloride / CH2Cl2 / 3 h / 0 °C 5.1: NaH / tetrahydrofuran / 0 - 20 °C 5.2: 72 percent / tetrahydrofuran / 19 h / 75 °C 6.1: 80 percent / LiI / dimethylformamide / 17 h / 130 °C 7.1: 39 percent / p-toluenesulfonic acid / methanol / 1.25 h / 20 °C View Scheme

1.1: 90 percent / NaOMe; MeOH / 24 h / 20 °C 2.1: 81 percent / triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran / 18 h / 20 - 40 °C 3.1: 85 percent / NaOMe; MeOH / 24 h / 20 °C 4.1: 99 percent / diisopropylethylamine; methanesulfonyl chloride / CH2Cl2 / 3 h / 0 °C 5.1: NaH / tetrahydrofuran / 0 - 20 °C 5.2: 75 percent / tetrahydrofuran / 19 h / 75 °C 6.1: 74 percent / LiI / dimethylformamide / 17 h / 130 °C 7.1: 59 percent / tetrabutylammonium fluoride / tetrahydrofuran / 2 h / 20 °C View Scheme

1.1: 90 percent / NaOMe; MeOH / 24 h / 20 °C 2.1: DMAP / dimethylformamide / 20 h / 100 °C 3.1: tetrabutylammonium fluoride / tetrahydrofuran / 2 h / 20 °C 4.1: triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran / 18 h / 20 - 40 °C 5.1: NaOMe; MeOH / 24 h / 20 °C 6.1: 93 percent / diisopropylethylamine; methanesulfonyl chloride / CH2Cl2 / 3 h / 0 °C 7.1: NaH / tetrahydrofuran / 0 - 20 °C 7.2: 74 percent / tetrahydrofuran / 19 h / 75 °C 8.1: 63 percent / LiI / dimethylformamide / 17 h / 130 °C 9.1: 54 percent / p-toluenesulfonic acid / methanol / 1.25 h / 20 °C View Scheme