An Efficient Procedure for Cleavage of T-Butyl Protected Cysteine in Solid Phase Peptide Synthesis

In the Fmoc-strategy of solid phase peptide synthesis, 1M trimethylsilyl bromide-thioanisole/trifluoroacetic acid in the presence of 1,2-ethanedithiol as scavenger was found to be an efficient deprotecting procedure for a full cleavage and side chains deprotection of the peptide resin involving t-butyl protected cysteine. In addition, selective deprotection of the peptide resin containing protected cysteine was also described based on this method.