The first synthesis of pennogenin, an aglycone of bioactive components of Chinese traditional medicine named Chonglou(Paris), starting from diosgenin, has been reported, which displays a new strategy of utilizing the resource compounds. According to this new strategy, the full and rational utilization of the intact skeleton and functional groups of starting material has been realized in the conversion of diosgenin to pennogenin. The key step for synthesis of pen-nogenin is the regioselective transformation of cholest-5-en-16,22-dion-3,26-diol to cholest- 5,16-dien-22-on-3,26-diol, which can be used to synthesize other bioactive steroids such as cephalostatin and OSW-1.
