title: New reagent system for attaining high regio- and stereoselectivities in allylic displacement of 4-cyclopentene-1,3-diol monoacetate with aryl- and alkenylmagnesium bromides.
abstract: [Reaction: see text] Low regioselectivity of RMgBr (R = aryl, alkenyl) in the CuCN-catalyzed reaction with 4-cyclopentene-1,3-diol monoacetate is improved by addition of LiCl or MgCl2 to a similar extent as previously obtained with RMgCl (>90:10). The limitation encountered in the preparation of RMgCl no longer exists in the present method using RMgBr. The method is utilized in the synthesis of AH-13205, a selective EP2-receptor agonist.
authors.affiliation: Department of Biomolecular Engineering, Tokyo Institute of Technology, Box B-52, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan. ykobayas@bio.titech.ac.jp
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Kenya
authors.initials: K
authors.lastname: Nakata
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ainai
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry*; D003517:Cyclopentanes / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D011466:Prostanoic Acids / Q000138:chemical synthesis; D013237:Stereoisomerism
chemical_list: C511439:4-cyclopentene-1,3-diol monoacetate; D000085:Acetates; D000475:Alkenes; D003517:Cyclopentanes; D009942:Organometallic Compounds; D011466:Prostanoic Acids; C081039:AH 13205; C067783:ethyl magnesium bromide