Abstract In this and the following two papers the synthesis of myxovirescins A 1, A 2 and M 2, 28-membered macrocyclic lactam-lactones with antibiotic acitivity, is described. A retrosynthetic analysis of the myxovirescin family of ca. 30 target molecules leads to a strategy which could be applied to approximately half of them by slight variations of the building blocks used (Schemes 1–3 and following paper). The southeastern part of the ...