title: A concise synthesis of furostifoline by tetrabutylammonium fluoride-promoted indole ring formation.
abstract: Furostifoline, a furo[3,2-a]carbazole alkaloid, was synthesized in 10% overall yield in four steps from 2-acetyl-3-bromofuran. The key step of this synthesis was the 2-substituted indole formation with tetrabutylammonium fluoride (TBAF) from 2-(2-propenyl)-3-((2-ethoxycarbonylamino)phenylethynyl)furan, which was easily prepared from ethyl 2-ethynylphenylcarbamate with 3-bromo-2-(2-propenyl)furan by the Sonogashira reaction.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Tohoku University Aobaku, Sendai, Japan. yasuhara@mail.pharm.tohoku.ac.jp
authors.forename: Akito
authors.initials: A
authors.lastname: Yasuhara
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Suzuki
authors.forename: Takao
authors.initials: T
authors.lastname: Sakamoto
mesh_terms: D002227:Carbazoles / Q000138:chemical synthesis* / Q000737:chemistry; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D007211:Indoles / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D002227:Carbazoles; D005663:Furans; D007211:Indoles; D000644:Quaternary Ammonium Compounds; C440197:furostifoline; C009405:tetrabutylammonium