87296-06-8Relevant academic research and scientific papers
Enantioface-differentiating protonation with chiral γ-hydroxyselenoxides
Takahashi, Tamiko,Nakao, Naoki,Koizumi, Toru
, p. 3293 - 3308 (2007/10/03)
Enantioface-differentiating protonation of a chiral metal enolates of α-alkylcarbonyl compounds 7 has been developed using chiral γ-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 7c 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.
Enzyme-mediated enantioface-differentiating hydrolysis of α-substituted cycloalkanone enol esters
Matsumoto, Kazutsugu,Tsutsumi, Seiji,Ihori, Tamiko,Ohta, Hiromichi
, p. 9614 - 9619 (2007/10/02)
A new type of enzymatic hydrolysis, enantioface-differentiating hydrolysis of enol esters, is disclosed. As a result of screening, Pichia miso IAM 4682, a type of yeast, was selected as the best strain to perform the enantioselective hydrolysis of enol esters to give α-chiral ketones. For example, incubation of 1-acetoxy-2-methylcyclohexene (4a) with P. miso afforded (S)-2-methylcyclohexanone (5) in high optical yield. This enzymatic hydrolysis is applicable to various α-substituted cycloalkanone enol esters, and thereby chiral six-, eight-, ten-, and twelve-membered-ring ketones of 70-96% enantiomeric excess (ee) are easily prepared.
