title: Kinetically controlled optical resolution of racemic norbornene aldehyde derivatives.
abstract: A new method for obtaining optically pure 5-norbornene 2-endo-aldehyde derivatives was developed. The reaction of a diastereomeric mixture of the ene acetals 2 and 2', derived from racemic norbornene aldehydes (+/-)-1 and chiral nonracemic (S,S)-hydrobenzoin 7, with NBS (0.5-0.6 eq.) in the presence of H(2)O proceeded in a kinetically controlled manner to give the optically pure hydroxy aldehydes 3 along with the intact ene acetals 2'. Both compounds 3 and 2' were converted into the optically pure norbornene aldehydes 1 and ent-1, respectively. This method opens the way to produce various types of 5-norbornene 2-endo-aldehydes with 3-exo- or 3-endo-substituents in optically pure forms.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan. fujioka@phs.osaka-u.ac.jp
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Fujioka
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Kotoku
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Fujita
authors.forename: Ryoko
authors.initials: R
authors.lastname: Inoguchi
authors.forename: Kenichi
authors.initials: K
authors.lastname: Murai
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Nagatomi
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Sawama
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kita
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D007202:Indicators and Reagents; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D009636:Norbornanes / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D007202:Indicators and Reagents; D009636:Norbornanes