- Conversion of spirostane and solanidane into pregnane (1) introduction of oxygen function into C-23
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A spirosolane derivative possessing a hydroxyl group at C-23, esculeogenin A, a sapogenol of tomato saponin, was found to be easily converted into the corresponding pregnane derivative by refluxing with aqueous pyridine. Therefore, introduction of a hydroxyl group into the C-23 of diosgenin (as representative of spirostane derivatives) and solasodine (as representative of spirosolane derivatives) was attempted by the reaction of NaNO2-BF3 · Et2O. In diosgenin, the objective compound was obtained by the reaction in AcOH. However, in solasodine, we obtained a 23-nitroso derivative by the reaction in AcOH and 23,24-bisnorcholanic acid 22-16 lactone, or vespertilin, in AcOH and CHCl3.
- Nakata, Nodoka,Tokudome, Asami,Yanai, Hiroyuki,Nohara, Toshihiro
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- Synthesis and plant growth promoting activity of dinorcholanic lactones bearing the 5α-hydroxy-6-oxo moiety
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The naturally occurring dinorcholanic lactone vespertilin and two other non-natural derivatives bearing the 5α-hydroxy-6-oxo moiety were synthesized starting from the readily available steroid sapogenin diosgenin. The obtained compounds showed plant growt
- Rosado-Abón, Anielka,De Dios-Bravo, Guadalupe,Rodríguez-Sotres, Rogelio,Iglesias-Arteaga, Martín A.
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- Peculiar side-chain fission of steroidal glycosides
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The characteristic novel steroidal glycosides of the 23,26-oxygenated spirostanol-type and 16,22-dicarbonyl cholestanol-type obtained in our laboratory underwent the peculiar reactions of side-chain fission between C-22 and C-23 of the steroidal skeleton
- Nafady, Alaa Mohamed,El-Shanawany, Mohamed Ahmed,Mohamed, Mahmoud Hamed,Hassanean, Hashim Abdel-Halim,Zhu, Xing-Hua,Yoshihara, Tsutomu,Okawa, Masafumi,Ikeda, Tsuyoshi,Nohara, Toshihiro
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