title: Facile synthesis of a benzindenoazepine alkaloid, bulgaramine, via samarium diiodide promoted ring expansion of an alpha-aminocarbonyl compound.
abstract: A novel synthetic path to a benzindenoazepine alkaloid was established by employing a samarium diiodide promoted ring expansion reaction of an alpha-aminocarbonyl compound as a key reaction, in which a regioselective carbon-nitrogen bond cleavage followed by ring-closing reactions occurred to give the basic ring skeleton of the target compound. Bulgaramine was synthesized from the known tetrahydroisoquinoline derivative in 5 steps in 50% overall yield.
authors.affiliation: Faculty of Pharmaceutical Sciences, Hoshi University, Ebara 2-4-41, Shinagawa-ku, Tokyo 142-8501, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Honda
authors.forename: Eriko
authors.initials: E
authors.lastname: Aranishi
authors.forename: Kyosuke
authors.initials: K
authors.lastname: Kaneda
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D001381:Azepines / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D031312:Fumaria / Q000737:chemistry; D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis* / Q000737:chemistry; D007454:Iodides / Q000737:chemistry*; D015394:Molecular Structure; D012493:Samarium / Q000737:chemistry*
chemical_list: D000470:Alkaloids; D001381:Azepines; D006576:Heterocyclic Compounds, 4 or More Rings; D007454:Iodides; C504701:benzindenoazepine; C504702:bulgaramine; D012493:Samarium; C409809:samarium diiodide