Synthesis of 22,25-epoxyfurostan sapogenins
1974
González, Antonio G. | Freire, Raimundo | Francisco, Cosme G. | Salazar, José A. | Hernández, Rosendo | Suárez, Ernesto
2 pages, 1 scheme.-- Part XXV in the series "New Sources of Steroid Sapogenins". For Part XXIV see A.G. González, R. Freire, C.G. Francisco, J.A. Salazar and E. Suárez, Anal. Quím 70, 250 (1974), available at: http://digital.csic.es/handle/10261/16426
显示更多 [+] 显示较少 [-]Several furostan sapogenins with oxygen bridge between C-22 and C-25 have been isolated, the stereochemistry of the side chain being 2OS,22S,25S in cholegenin, nuatigenin, afurigenin, funchaligenin and androgenin A, and 20S,22S,25R in androgenin B and 25R-funchaligenin. As no efficient syntheses of this type of compounds are known till now, we have prepared the 25S- and 25R-stereoisomers of (20S,22S)-furostan-22,25-epoxy-26-ol (IVa and IVb) from (25R)-5α-spirostan (I) by a simple method (overall yield 60%) which may easily be used to obtain other compounds of the same series.
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