Synthesis
Fmoc(OTIPS) benzyl ester (0.87 g, 1.48 mmol) is dissolved in 7.4 mL dry CH2Cl2 under an argon atmosphere. The solution is cooled to 0°C and 7.4 mL of 40% (v/v) Piperidine solution in dry CH2Cl2 is added dropwise. After 15 min of stirring at 0°C, the mixture is concentrated in vacuo at 25°C to an oil and put immediately onto the silica column (cyclohexane/EtOAc 5: 1 + 0.5% NEt3, elution of product with 1: 1 + 0.5% NEt3). The yield of Fmoc-Thr-Obzl is 0.44 g (1.20 mmol, 81%) as a colorless oil.
