The modelstudies of uracil group introduction for liposidomycin degradation product was described. A stereocontrolledsynthesis of the liposidomycin diazepanone ring system having a phenyl substituent has been achieved. In the presence of an amino group on the diazepanone ring, the introduction of a uracil group did failed. In the modelstudy with the Ns and formyl protecting group, the N-glycosylation