作者:Tamiko Takahashi、Naoki Nakao、Toru Koizumi
DOI:10.1016/s0957-4166(97)00423-0
日期:1997.10
Enantioface-differentiating protonation of achiral metal enolates of alpha-alkylcarbonyl compounds 7 has been developed using chiral gamma-hydroxyselenoxides 1 as a proton source. Reaction of zinc bromide enolates of 2-benzyl- and 2-n-propylcyclohexanones with (S-se)-1e gave (S)-2-benzylcyclohexanone 7a and (R)-2-n-propylcyclohexanone 7e in high enantiomeric excess, respectively. Intramolecular hydrogen bonding of the selenoxide 1, chelation effects between 1 and metal enolate, and 2-exo-hydroxy-10-bornyl-framework could contribute to this asymmetric induction. (C) 1997 Elsevier Science. Ltd.