[Synthesis of (LysA13)bovine insulin A chain analogs as (Lys(Tfa)A13)A(SO3H)4 and Nalpha-A1-Msc-(LysA13)A(SO3H)4 derivatives using the S-tert-butylmercapto residue for thiol protection (author's transl)].

The following paper describes the synthesis of the [LysA13]bovine insulin A chain analog as [Lys(Tfa)A13]A(SO3H)4 and NalphaA1-Msc-[LysA13]A(SO3H)4 derivatives using the S-tert-butylmercapto residue for thiol protection. Although the intermediate S-tert-butylmercaptocysteinyl-peptide derivatives showed a good solubility in organic solvents the resulting fully protected A chain derivatives had a poor solubility in organic solvents and therefore were deblocked converted into the tetra(S-sulfonic acid) derivatives and purified via ionexchange chromatography.