title: Rapid conversion of spirostans into furostan skeletons at room temperature.
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.
authors: Universidad del Papaloapan, Colonia Parque Industrial, Tuxtepec, Oax., México CP, Mexico.
authors: Omar
authors: O
authors: Viñas-Bravo
authors: Roxana
authors: R
authors: Martinez-Pascual
authors: José Luis
authors: JL
authors: Vega-Baez
authors: Víctor
authors: V
authors: Gómez-Calvario
authors: Jesús
authors: J
authors: Sandoval-Ramírez
authors: Sara
authors: S
authors: Montiel-Smith
authors: Socorro
authors: S
authors: Meza-Reyes
authors: Alejandra
authors: A
authors: López-De Rosas
authors: Mónica
authors: M
authors: Martínez-Montiel
authors: Mayra
authors: M
authors: Reyes
authors: José A
authors: JA
authors: Ruiz
mesh_terms: D000089:Acetic Anhydrides; D000972:Antineoplastic Agents, Phytogenic / Q000032:analysis / Q000138:chemical synthesis*; D001557:Benzenesulfonates / Q000737:chemistry; D001880:Boranes / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D003486:Cyanides / Q000737:chemistry; D005463:Fluoroacetates; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol / Q000737:chemistry; D015394:Molecular Structure; D012502:Sapogenins / Q000032:analysis / Q000138:chemical synthesis*; D013150:Spirostans / Q000032:analysis / Q000737:chemistry*; D013237:Stereoisomerism; D013696:Temperature; D014269:Trifluoroacetic Acid / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D000089:Acetic Anhydrides; D000972:Antineoplastic Agents, Phytogenic; D001557:Benzenesulfonates; D001880:Boranes; D003486:Cyanides; D005463:Fluoroacetates; D012502:Sapogenins; D013150:Spirostans; D014867:Water; C101707:boron trifluoride etherate; C017958:trifluoroacetic anhydride; D014269:Trifluoroacetic Acid; C029501:4-toluenesulfonic acid; D000432:Methanol