Summary. Coroglaucigenin, which is known to be a 3j3,14j3,19-trihydroxy-5cr-card-20 : 22-enolid, was transformed into Zcr, 3j3,19-triacetoxy-14j3-hydroxy-5a-card-20 : 22-enolid. The latter was identical with the known tri-0-acetyl-19-dihydro-calotropagenin. The structure of calotropagenin (1) is thus established through an independent way.