Facile synthesis of 12-carboxamido-11-spirostenes via palladium-catalyzed carbonylation reactions

• Autor(a) principal: Ács, Péter
• Data de Publicação: 2006
• Outros Autores: Müller, Erno, Czira, Gábor, Mahó, Sándor, Pereira, Mariette, Kollár, László
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• DOI: 10.1016/j.steroids.2006.05.019
• Texto Completo: http://hdl.handle.net/10316/5072; https://doi.org/10.1016/j.steroids.2006.05.019
• topic: Iodo-alkenene; Carboxamide; Hecogenin; Palladium-catalyst; Carbonylation

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.