Mild, selective cleavage of amino acid and peptide β-(trimethylsilyl)ethoxymethyl (SEM) esters by magnesium bromide

Article abstract of DOI:10.1016/S0040-4039(97)00863-0

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 sensitive protecting groups to magnesium bromide allows for added selectivity in the removal of SEM esters in organic synthesis.