Preparation of Enantiopure Ketones and Alcohols Containing a Quaternary Stereocenter through Parallel Kinetic Resolution of β-Keto Nitriles
摘要:
Racemic 1-methyl-2-oxocycloalkanecarbonitriles have been subjected to bioreduction by the fungus Mortierella isabellina NRRL 1757 through a parallel kinetic-resolution process. The u and l alcohols thus obtained (up to >99% ee) were easily separated and oxidized to the R and S ketones, respectively. The process can be then repeated so that both enantiomers of the ketone and two epimers of the alcohol can be obtained in their enantiopure forms.
Preparation of Enantiopure Ketones and Alcohols Containing a Quaternary Stereocenter through Parallel Kinetic Resolution of β-Keto Nitriles
摘要:
Racemic 1-methyl-2-oxocycloalkanecarbonitriles have been subjected to bioreduction by the fungus Mortierella isabellina NRRL 1757 through a parallel kinetic-resolution process. The u and l alcohols thus obtained (up to >99% ee) were easily separated and oxidized to the R and S ketones, respectively. The process can be then repeated so that both enantiomers of the ketone and two epimers of the alcohol can be obtained in their enantiopure forms.
2-Alkyl-2-cyanocycloalkanones 4 bearing a quaternary stereogenic center are synthesized in good overall yields and high enantiomeric excesses (ee = 90-95%) employing the SAMP-/RAMP-hydrazone method. The absolute configuration is confirmed by NMR-spectroscopic investigations on SAMP-hydrazone 3a and an X-ray structure analysis of SAMP-hydrazone 3f.
Enders Dieter, Zamponi Andrea, Raabe Gerhard, Runsink Jan, Synthesis, (1993) N 7, S 725-728
作者:Enders Dieter, Zamponi Andrea, Raabe Gerhard, Runsink Jan
DOI:——
日期:——
Preparation of Enantiopure Ketones and Alcohols Containing a Quaternary Stereocenter through Parallel Kinetic Resolution of β-Keto Nitriles
作者:Juan R. Dehli、Vicente Gotor
DOI:10.1021/jo011092t
日期:2002.3.1
Racemic 1-methyl-2-oxocycloalkanecarbonitriles have been subjected to bioreduction by the fungus Mortierella isabellina NRRL 1757 through a parallel kinetic-resolution process. The u and l alcohols thus obtained (up to >99% ee) were easily separated and oxidized to the R and S ketones, respectively. The process can be then repeated so that both enantiomers of the ketone and two epimers of the alcohol can be obtained in their enantiopure forms.