Steroids 2012-01-01

Rapid conversion of spirostans into furostan skeletons at room temperature.

Omar Viñas-Bravo, Roxana Martinez-Pascual, José Luis Vega-Baez, Víctor Gómez-Calvario, Jesús Sandoval-Ramírez, Sara Montiel-Smith, Socorro Meza-Reyes, Alejandra López-De Rosas, Mónica Martínez-Montiel, Mayra Reyes, José A Ruiz

Index: Steroids 77(1-2) , 59-66, (2012)

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Abstract

We report a facile protocol to obtain 22-substituted furostans and pseudosapogenins in high yields from (25R)- and (25S)-sapogenins. This method involves the treatment of the sapogenin with acetic-trifluoroacetic mixed anhydride and BF(3)·OEt(2) at room temperature, followed by the addition of a nucleophile (H(2)O, MeOH or KSeCN). In the case of 22-hydroxyfurostans, they can be transformed to pseudosapogenins by treatment with p-toluensulfonic acid.Copyright © 2011 Elsevier Inc. All rights reserved.