172277-49-5Relevant academic research and scientific papers
Enantioselective synthesis of functionalized tropanes by rhodium(II) carboxylate-catalyzed decomposition of vinyldiazomethanes in the presence of pyrroles
Davies, Huw M. L.,Matasi, Julius J.,Mark Hodges,Huby, Nicholas J. S.,Thornley, Craig,Kong, Norman,Houser, Jeffrey H.
, p. 1095 - 1105 (1997)
A series of enantiomerically enriched tropanes was synthesized by the rhodium(II) octanoate-catalyzed reaction of various N-BOC-protected pyrroles with vinyldiazomethanes. The overall 3 + 4 annulation occurs by a tandem cyclopropanation/Cope rearrangement. Asymmetric induction was best achieved in these transformations by using either (S)-lactate or (R)-pantolactone as a chiral auxiliary on the vinyldiazomethanes. Reactions carried out with the chiral catalyst tetrakis-[N-(4-tert-butylbenzenesulfonyl)-(L)-prolinato]dirhodium (2) provided moderate asymmetric induction, but also resulted in the formation of isomeric azabicyclooctane side products. The utility of the synthetic process was demonstrated through the asymmetric synthesis of (-)-anhydroecgonine methyl ester and (-)-ferruginine.
Total synthesis of (-)-cocaine and (-)-ferruginine
Cheng, Guolin,Wang, Xinyan,Zhu, Rui,Shao, Changwei,Xu, Jimin,Hu, Yuefei
, p. 2694 - 2700 (2011/06/20)
Total synthesis of tropane alkaloids (-)-cocaine and (-)-ferruginine were accomplished in nine steps each and in 55% and 46% overall yields, respectively, starting from the known Betti base derivative (+)-(7aR,10R,12S)-10-(1H- benzotriazol-1-yl)-7a,8,9,10-tetrahydro-12-phenyl-12H-naphtho[1,2-e]pyrrolo[2, 1-b][1,3]oxazine. In this novel route, RCM reaction and 1,3-dipolar cycloaddition were employed as key steps for the enantioselective construction of tropane skeleton and the regioselective introduction of 3-bromo-2-isoxazoline ring as masked cis-2,3-disubstituents. To obtain the desired precursor (2S,5R)-2-allyl-5-vinylpyrrolidine for RCM reaction, we developed a general and practical method for the preparation of enantiopure cis-2,5-disubstituted pyrrolidines bearing alkene- and/or alkyne-containing substituents. We also offered two highly efficient pathways for the conversion of the 3-bromo-2-isoxazoline ring into the desired cis-2,3-disubstituted groups in (-)-cocaine and (-)-ferruginine.
Formal synthesis of (+)- and (-)-ferruginine
Piccardi, Riccardo,Renaud, Philippe
, p. 4752 - 4757 (2008/03/13)
A formal synthesis of the naturally occurring (+)-ferrugine and of its enantiomer starting from the commercially available tropinone is reported. The desymmetrization of tropinone was achieved through formation of diastereomeric unsaturated sulfoxides usi
Enantiospecific synthesis of (+)- and (-)-ferruginine from L-glutamic acid. Synthesis of tropanes via intramolecular iminium ion cyclization
Hernandez, Andres S.,Thaler, Adrian,Castells, Josep,Rapoport, Henry
, p. 314 - 323 (2007/10/03)
Iminium ions, generated by decarbonylation of N-benzyl-5-[1-(methoxycarbonyl)-4-oxopentyl]prolines, undergo intramolecular cyclization to afford 2,4-disubstituted tropanes in good yields. This transformation is also shown to be a stereospecific reaction. The value of these substituted tropanes has been demonstrated by functional group manipulation, leading to the enantiospecific synthesis of (±)-ferruginine, an alkaloid isolated from Darlinga ferruginea, and its unnatural enantiomer, (-)-ferruginine.
