Viñas-Bravo O, Martinez-Pascual R, Vega-Baez JL, Gómez-Calvario V, Sandoval-Ramírez J, Montiel-Smith S, Meza-Reyes S, López-De Rosas A, Martínez-Montiel M, Reyes M, Ruiz JA. Rapid conversion of spirostans into furostan skeletons at room temperature.
Steroids 2012;
77:59-66. [PMID:
22061618 DOI:
10.1016/j.steroids.2011.10.004]
[Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 09/20/2011] [Accepted: 10/13/2011] [Indexed: 10/16/2022]
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.
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