title: On the reactivity of 23-methoxycarbonyl furospirostanes.
abstract: Brønsted and Lewis acid-catalysed reactions of the 23-methoxycarbonyl furospirostanic side chain are described. While bromination, deuteration and BF(3)·Et(2)O/AcOH treatment involve regioselective F-ring opening with exclusive participation of Δ(22)-furostenic intermediates, BF(3)·Et(2)O/Ac(2)O treatment leads to irreversible E- or F-ring cleavage.
authors.affiliation: Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 Mexico, DF, Mexico.
authors.forename: Mariana
authors.initials: M
authors.lastname: Macías-Alonso
authors.forename: Marcos
authors.initials: M
authors.lastname: Flores-Álamo
authors.forename: Martin A
authors.initials: MA
authors.lastname: Iglesias-Arteaga
mesh_terms: D054879:Halogenation; D058116:Lewis Acids / Q000737:chemistry; D015394:Molecular Structure; D013150:Spirostans / Q000737:chemistry*
chemical_list: D058116:Lewis Acids; D013150:Spirostans