Synthese von Peptid‐Zwischenprodukten für den Aufbau eines corticotrop wirksamen Nonadecapeptids. II. Derivate des L ‐Seryl‐ L ‐tyrosyl‐ L ‐serins

The synthesis of t‐butyloxycarbonyl derivatives of L‐seryl‐L‐tyrosyl‐L‐serine and L‐seryl‐L‐tyrosyl‐L‐seryl‐L‐methionine is described. The azide method involving the conversion of a hydrazide into the corresponding azide under acidic conditions was found to be applicable, under carefully selected conditions, to the synthesis of t‐butyloxycarbonyl peptide derivatives in spite of the sensitivity of the protecting group toward strongly acidic reagents.