The absolute configurations of rubeomycins A and A1(corresponding to carminomycins II and III) and rubeomycins B and B1(corresponding to 4-hydroxybaumycinols A1and A2), except at the C-1″ position, were determined by comparison of the optical rotations and other spectral data of rubeomycin derivatives with those of daunomycin and L-(+)-lactic acid.
