title: Facile synthesis of 12-carboxamido-11-spirostenes via palladium-catalyzed carbonylation reactions.
abstract: 12-Carboxamido- and 12-carboxyl-11-spirostenes were synthesized from the corresponding 12-iodo-11-ene derivative in palladium-catalyzed carbonylation reactions under mild reaction conditions. The synthesis of the iodo-alkene substrate is based on the transformation of the 12-keto derivative (hecogenin) to hydrazone, which was treated with iodine in the presence of a base (1,1,3,3-tetramethyl guanidine). While various 12-carboxamides were synthesized in moderate to high yields by using simple alkyl/arylamines or amino acid methylesters as N-nucleophiles, low yields can be achieved with alcohols as O-nucleophiles. The homogeneous carbonylation reactions tolerate the 3-hydroxy substituent and the spiroacetal moiety.
authors.affiliation: University of Pécs, Department of Inorganic Chemistry, Ifjúság u.6., H-7624 Pécs, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Acs
authors.forename: Erno
authors.initials: E
authors.lastname: Müller
authors.forename: Gábor
authors.initials: G
authors.lastname: Czira
authors.forename: Sándor
authors.initials: S
authors.lastname: Mahó
authors.forename: Mariette
authors.initials: M
authors.lastname: Perreira
authors.forename: László
authors.initials: L
authors.lastname: Kollár
mesh_terms: D002384:Catalysis; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010165:Palladium / Q000737:chemistry*; D013150:Spirostans / Q000138:chemical synthesis*
chemical_list: D007659:Ketones; D013150:Spirostans; D010165:Palladium