Synthesis of the protected nonapeptide tert-butyloxycarbonyl-~-leucyl-~-glutaminyl-, l'~-2, 6- dichlorobeneyloxy-carbonyl-~-lysyl-t-leucyl-~-leucyl-~-glutaminylglycyl-~ leucyl-~- valinamide, corresponding to the C-terminal sequence of a secretin analog, is described. Acylation of L-valinamide with the o-nitrophenyl ester of tert-butyloxycarbonyl-L-leucine yielded a dipeptide derivative which, after deprotection with trifluoroacetic acid, was ...