macrocyclodepsipeptides fromsimple and readily available starting materials has been developed. The sequence consists of (a) a three-component reaction of an aldehyde, an amino alc., and a dipeptide isocyanate and (b) a domino process involving an activation of the terminal carboxylic acid function by a built-in aminooxazole followed by a macrocyclization under acidic conditions. The synthesis is atom-economic