1.1: NaN(SiMe3)2 / tetrahydrofuran / 1 h / -75 °C 1.2: 61 percent / tetrahydrofuran / -70 - -50 °C 2.1: 97 percent / aq. H2O2; LiOH / tetrahydrofuran / 0 - 20 °C View Scheme

1.1: NaN(SiMe3)2 / tetrahydrofuran / 1 h / -75 °C 1.2: 61 percent / tetrahydrofuran / -70 - -50 °C 2.1: 97 percent / aq. H2O2; LiOH / tetrahydrofuran / 0 - 20 °C 3.1: 99 percent / N-(dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride; i-Pr2NEt; 1-hydroxy-1,2,3-benzotriazole hydrate / CH2Cl2 / 4 - 20 °C 4.1: 80 percent / TFA / CH2Cl2 / 2 h / 20 °C View Scheme

1.1: NaN(SiMe3)2 / tetrahydrofuran / 1 h / -75 °C 1.2: 61 percent / tetrahydrofuran / -70 - -50 °C 2.1: 97 percent / aq. H2O2; LiOH / tetrahydrofuran / 0 - 20 °C 3.1: 99 percent / N-(dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride; i-Pr2NEt; 1-hydroxy-1,2,3-benzotriazole hydrate / CH2Cl2 / 4 - 20 °C View Scheme