Direct Synthesis of Polycyclic Tropinones by a Condensation–[4+3]‐Cycloaddition Cascade Reaction. Issue 38 (10th June 2018)

• Record Type: Journal Article
• Authors: Okamoto, Tsubasa; Shibata, Miki; Karanjit, Sangita; Nakayama, Atsushi; Yoshida, Masahiro; Namba, Kosuke
• Is Part Of: Chemistry. Volume 24:Issue 38(2018)
• Page Start: 9508
• Page End: 9513
• Publication Date: 2018-06-10
• Subjects: cycloaddition -- oxyallyl cation -- pyrrole -- synthetic methods -- tropane alkaloid; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201802011
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: A concise method of constructing polycyclic tropinone frameworks was developed. The single‐step synthesis of polycyclic tropinone consists of an intramolecular [4+3] cycloaddition reaction of N ‐nosyl‐pyrrole with oxyallyl cation that was generated in situ by an intermolecular condensation reaction of the nucleophilic functional groups on a tethered pyrrole with the aldehyde of 2‐(silyloxy)‐acrolein. This cascade reaction afforded various polycyclic tropinones including tri‐, tetra‐, and pentacyclic systems in high yields as single diastereomers. Abstract : Building bridges : A concise method of constructing polycyclic tropinone frameworks was developed. The single‐step synthesis of polycyclic tropinone was accomplished by the cascade reaction of condensation and [4+3] cycloaddition reaction of N ‐nosyl‐pyrrole with an oxyallyl cation generated in situ, and this cascade reaction afforded various polycyclic tropinones including tri‐, tetra‐, and pentacyclic systems in high yields as single diastereomers.