title: Tuning efficiency of the 4-exo-trig cyclization by the electronic effect: ring closure of 3,3-difluoro-4-pentenyl carbon radicals and synthesis of a gem-difluorocyclobutane nucleoside.
abstract: 4-exo-trig Cyclization reaction of a 4-pentenyl carbon radical containing the gem-difluoromethylene moiety adjacent to a radical accepting α,β-unsaturated ester was found to proceed efficiently to furnish a novel gem-difluorocyclobutane derivative. The cyclized product could be transformed into a gem-difluoromethylene analogue of oxetanocin T.
authors.affiliation: School of Pharmacy, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan. kumamoto@pharm.showa-u.ac.jp
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kumamoto
authors.forename: Sachiko
authors.initials: S
authors.lastname: Kawahigashi
authors.forename: Hiromi
authors.initials: H
authors.lastname: Wakabayashi
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Nakano
authors.forename: Tomoko
authors.initials: T
authors.lastname: Miyaike
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kitagawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Abe
authors.forename: Mika
authors.initials: M
authors.lastname: Ito
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Haraguchi
authors.forename: Jan
authors.initials: J
authors.lastname: Balzarini
authors.forename: Masanori
authors.initials: M
authors.lastname: Baba
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry; D002073:Butanes / Q000138:chemical synthesis / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D003500:Cyclization; D005461:Fluorine / Q000737:chemistry*; D005609:Free Radicals; D015394:Molecular Structure; D009705:Nucleosides / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D000475:Alkenes; D002073:Butanes; D005609:Free Radicals; D009705:Nucleosides; C051061:oxetanocin; D005461:Fluorine; C046888:butane; D002244:Carbon; D000225:Adenine