Epimerization of C-22 in (25R)- and (25S)-sapogenins
作者:Omar Viñas-Bravo、Penélope Merino-Montiel、Anabel Romero-López、Sara Montiel-Smith、Socorro Meza-Reyes、Francisco J. Meléndez、Jesús Sandoval-Ramírez
DOI:10.1016/j.steroids.2014.10.004
日期:2015.1
Most of the naturally occurring steroidalsapogenins (C-23 non-substituted frameworks), possess an R configuration at the spiro C-22 center. Their C-22 epimers have become important targets in biological research. This paper describes a procedure to obtain 22S-spirostans from 22R-sapogenins and pseudosapogenin skeletons, without affecting the chirality at either C-25 or C-20. An optimal way to synthesize