Absolute configuration of calogenin and its 20-keto derivative

The absolute configuration of calogenin (isolated from Periploca calophylla) and its 20-keto derivative (isolated from Hemedesmus indicus) has been established as pregn-5-cne-3β, 14β, 20R triol containing a C-17 hydroxy ethyl chain in α-configuration and pregn-5-ene-20-keto-3β,14β-diol containing a C-17 methyl keto chain in β-configuration, respectively.