1.1: titanium tetrachloride / tetrahydrofuran / 3.5 h / -40 - 20 °C 2.1: triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran / -20 °C 3.1: toluene-4-sulfonic acid; methanol / 4 h / 0 - 20 °C 4.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 1.5 h / 20 °C 5.1: sodium hydroxide; water / 3.5 h / 72 °C 5.2: 0 °C / pH 6.3 View Scheme

1.1: titanium tetrachloride / tetrahydrofuran / 3.5 h / -40 - 20 °C 2.1: triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran / -20 °C 3.1: toluene-4-sulfonic acid; methanol / 4 h / 0 - 20 °C 4.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 1.5 h / 20 °C 5.1: sodium hydroxide; water / 3.5 h / 72 °C 5.2: 0 °C / pH 6.3 View Scheme