[EN] PROCESS FOR THE SYNTHESIS OF DISTAMYCIN AND DERIVATIVES THEREOF USING 1-METHYL-4-FORMYLAMINO-2-PYRROLECARBONYL CHLORIDE ITERATIVELY AS AN INTERMEDIATE [FR] PROCEDE DE SYNTHESE DE DISTAMYCINE ET DE SES DERIVES AU MOYEN DE CHLORURE DE 1-METHYL-4-FORMYLAMINO-2-PYRROLECARBONYLE DE FACON REPETEE EN TANT QU'INTERMEDIAIRE