The synthesis of a 24-membered cyclic depsipeptide with an alternating sequence of phenyllactic acid and α-aminoisobutyric acid (Aib) is described. The linear precursor was prepared via the ‘azirine/oxazolone method’ using 2,2-dimethyl-3-amino-2H-azirines as building blocks for the α,α-disubstituted α-amino acid Aib. The macrolactonization leading to the cyclodepsipeptide was achieved by the ‘direct amide cyclization’, i. e., by treatment of a solution of the linear precursor in toluene with HCl gas.