title: Enantioselective, desymmetrizing, bromolactonization reactions of symmetric olefinic dicarboxylic acids.
abstract: The results of studies leading to the development of enantioselective desymmetrizing, bromolactonization reactions of symmetric olefinic dicarboxylic acids, which are promoted by a C3 -symmetric trisimidazoline catalyst, are described. These processes generated carboxylic-acid-containing bromolactones in moderately high enantiomeric excesses. The results of optimization studies showed that reactions in a mixed solvent system of toluene and acetone proceeded with the highest levels of enantioselectivity. NMR studies probing the interactions between the catalyst and dicarboxylic acid substrates, as well as the effect of acetone on the stereochemistry of the process, are also described.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University, 1-6, Yamada-oka, Suita, Osaka, 565-0871 (Japan), Fax: (+81) 6-6879-8229. murai@phs.osaka-u.ac.jp.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Murai
authors.forename: Junki
authors.initials: J
authors.lastname: Nakajima
authors.forename: Akira
authors.initials: A
authors.lastname: Nakamura
authors.forename: Norimichi
authors.initials: N
authors.lastname: Hyogo
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Fujioka
mesh_terms: D000096:Acetone / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D003998:Dicarboxylic Acids / Q000737:chemistry*; D006842:Hydrocarbons, Brominated / Q000138:chemical synthesis* / Q000737:chemistry; D048288:Imidazolines / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D003998:Dicarboxylic Acids; D006842:Hydrocarbons, Brominated; D048288:Imidazolines; D000096:Acetone
keywords: asymmetric synthesis; bromolactonization; carboxylic acids; desymmetrization; organocatalysis