IMPROVED DEPROTECTION IN SOLID PHASE PEPTIDE SYNTHESIS: REMOVAL OF PROTECTING GROUPS FROM SYNTHETIC PEPTIDES BY AN SN2 MECHANISM WITH LOW CONCENTRATIONS OF HF IN DIMETHYLSULFIDE

Article abstract of DOI:10.1016/S0040-4039(00)85621-X

The use of a low-concentration HF in dimethylsulfide (1:3, v/v) for the removal of protecting groups from synthetic peptides has been found to be efficient and to eliminate several side reactions associated with the high-concentration HF in anisole (9:1, v/v) normally employed in peptide synthesis.The mechanism of the low-concentration HF cleavage is S_N2, in contrast to the S_N1 mechanism of the high-concentration HF cleavage, and consequently the reaction proceeds without generation of carbocation intermediates.