Trifluoromethanesulfonic acid → Fmoc-Ser-OTce

Participants

Reaction Steps

Fmoc-Ser-OTce (0.83 g, 1.8 mmol) was dissolved in CH2Cl2-Hexane (2:1, 4 mL), and 1,1-dimethylpropinyl trichloroacetimidate (0.41 g, 1.8 mmol, 1 equiv) and CF3SO3H (40 μl) were added under N2 atmosphere. The reaction mixture was allowed to stir for 4 days adding the same quantities of the trichloroacetimidate and CF3SO3H every 24 h. The reaction mixture was filtered and the filtrate was concentrated in vacuo, dissolved in EtOAc (10 mL) and washed with saturated aqueous NaHCO3 (2×10 mL), H2O (2×10 mL) and brine (2×10 mL). The organic solution was dried (MgSO4) and concentrate in vacuo to obtain the 1,1-dimethylpropinyl ether of Fmoc-Ser-OTce (0.95 g), which was used without further purification.

Provenance & Evidence