1.1: water; lithium hydroxide hydrate / tetrahydrofuran / 20 °C 1.2: pH 5 2.1: N-ethyl-N,N-diisopropylamine; HATU / N,N-dimethyl-formamide / 0.5 h / 20 °C 2.2: 0.5 h / 20 °C 3.1: trifluoroacetic acid / dichloromethane / 2 h / 20 °C View Scheme