TMOB SIDE CHAIN-PROTECTED S-CYSTEINE-CYSTEINESULFONAMIDES AND HOMO-S-CYSTEINESULFONAMIDES, THEIR N(ALPHA)-PROTECTED AND N(OMEGA)-AMINOETHYLATED DERIVATIVES

The 2,4,6-trimethoxybenzyl (Tmob) group is very suitable for temporary protection of the aminosulfonyl group of S-cysteine- and homo-S-cyste inesulfonamides. Both the introduction and removal of the Tmob-protect ing group can be achieved in high yields. 2-Aminoethyl derivatization of the aminosulfonyl group of S-cysteine- and homo-S-cysteinesulfonami des has been carried out, and various derivatives useful for peptide s ynthesis with Z, Boc and Fmoc as N(alpha)-protecting groups have been prepared. In all cases, a racemic mixture of S-cysteine- or homo-S-cys teinesulfonic acid has been used and subsequent enantiomer resolution has been achieved by treatment with Bacillus subtilis alkaline proteas e.