19-ETHYL-19-HYDROXY-14,18-DIOXO-17-OXA-3,13-DIAZAPENTACYCLO(11.8.0.02,11.04,9.015,20)HENICOSA-1(21),2(11),3,5,7,9,15(20)-HEPTAENE-6-CARBALDEHYDE, (19S)-
19-ethyl-19-hydroxy-14,18-dioxo-17-oxa-3,13-diazapentacyclo(11.8.0.02,11.04,9.015,20)henicosa-1(21),2(11),3,5,7,9,15(20)-heptaene-6-carbaldehyde, (19s)-