Convenient synthesis of (2R)- and (2S)-2-(1-methylethyl)-5-oxo-2-phenylpentanenitrile, intermediates in the preparation of phenylalkylamine calcium channel blockers
The multigram synthesis of (2S)- and (2R)-2-(1-methylethyl)-5-oxo-2-phenylpentanenitriles 9a and 9b is described, using either (4R)-2,2-dimethyl-1,3-dioxolan-4-ylmethanol or (2R)-butane-1,2,4-triol as chiral auxiliary, The configuration of an intermediate dioxolane 10b is assigned by X-ray crystallo...
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Published in | Journal of the Chemical Society, Perkin Transactions 1 no. 23; pp. 2845 - 2850 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
CAMBRIDGE
Royal Soc Chemistry
1996
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Subjects | |
Online Access | Get full text |
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Summary: | The multigram synthesis of (2S)- and (2R)-2-(1-methylethyl)-5-oxo-2-phenylpentanenitriles 9a and 9b is described, using either (4R)-2,2-dimethyl-1,3-dioxolan-4-ylmethanol or (2R)-butane-1,2,4-triol as chiral auxiliary, The configuration of an intermediate dioxolane 10b is assigned by X-ray crystallography. The synthetic utility of the aldehydes is demonstrated by conversion to both enantiomers of the calcium antagonist noremopamil in >98% enantiomeric excess (ee). The enantiomeric purity of the final amines is assayed by H-1 NMR spectroscopy in the presence of the chiral solvating agent (1R)-(-)-2,2,-trifluoro-1-(9-anthryl)ethanol. |
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ISSN: | 0300-922X 1364-5463 |
DOI: | 10.1039/p19960002845 |