Selective hydroxylation of di- and tri-peptides bearing alkyl side chains by methyl(trifluoromethyl)dioxirane

ORGN 919

Maria Rosaria Rella and Paul G. Williard, paul_williard@brown.edu. Department of Chemistry, Brown University, 324 Brook Street, Providence, RI 02912
Representative small Boc-protected and acetyl-protected peptide methyl esters bearing alkyl side chains undergo effective oxidation using methyl(trifluoromethyl)dioxirane 1b under mild conditions. We observe a protecting group dependency in the chemoselectivity displayed by the dioxirane 1b: N-hydroxylation occurs in the case of the Boc-protected peptides, and side chain hydroxylation takes place in the case of acetyl-protected peptides. Both are attractive transformations since they give easy access to valuable synthons in hydroxamate and polypeptide preparations and can be used in the development of peptide derivatives of biological relevance.