Magnesium bromide etherate has been previously shown to cleave β-(trimethylsilyl) ethoxymethyl (SEM) esters of aliphatic acids. This methodology has now been extended to amino acid and peptide derivatives in the presence of protecting groups typically encountered in peptide chemistry, including the Boc, Cbz, Fmoc and Troc carbamates as well as benzyl-, tert-butyl-and tert-butyldimethylsilyl ethers. The stability of fluoride ...