I 10 li nitro-3-benzyloxy-4-methylbenzoyl) threonyl-D-valine hydrazide (5) which yielded lg on reduction and oxidative dimerization. This hydrazide 5 was also the precursor for the bis- tripeptide analogue lh. The azide generated from 5 was coupled with proline methyl ester to give the tripeptide 6 which was reduced and oxidatively coupled to give lh. In order to prepare the final bis-tripeptide analogue li, it was first necessary to prepare a suitably ...