The Synthesis of a Partial Sequence of Proinsulin Using the A-Chain of Natural Insulin

Elongation reactions of the S-sulfonate of the A-chain of bovine insulin were carried out with acylamino acid-active esters or with acylpeptide azide; the following derivatives of the A-chain were thus synthesized: S-sulfonates of NG-nitro-l-arginyl-, l-lysyl-NG-nitro-l-arginyl-, and l-prolyl-l-prolyl-l-glutaminyl-Nε-benzyloxycarbonyl-l-lysyl-NG-nitro-l-arginyl-A-chain. Thus, this was demonstrated to be a useful procedure for the partial synthesis of proinsulin.