- SUBSTITUTED HETEROCYCLIC COMPOUNDS AS ION CHANNEL MODULATORS
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The present invention relates to sodium channel inhibitors of Formula (I): in which R1, R2, R3, R4, R5, X, Y, and Z are as defined herein, and to their use in the treatment of various disease states,
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Page/Page column 13
(2010/06/13)
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- Highly selective resolution of secondary alcohols and acetoacetates with lipases and diketene in organic media
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By the catalysis of lipases, racemic 1-phenylethanol 1a is reacted with diketene in isopropyl ether at room temperature to give (S)-1a (R1 = Me, R2 = Ph, 36%, 99% ee) and (R)-1-phenylethyl acetoacetate 2a (51%, 77% ee). The strategy was also successfully applied to racemic 1-(1-naphthyl)ethanol 1b, 1-(2-naphthyl)ethanol 1c, 1-phenyl-2-propanol 1d, 1,2,3,4-tetrahydro-1-naphthol 1e, and 2-octanol 1f with high E-values up to > 100.
- Suginaka, Kaoru,Hayashi, Yoshiyuki,Yamamoto, Yukio
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p. 1153 - 1158
(2007/10/03)
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- Yeast-Mediated Resolution of β-Keto Esters of Prochiral Alcohols
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Several racemic alcohols were converted to their β-keto esters with diketene, and the resulting compounds were subjected to kinetic resolution by means of baker's yeast.The unreacted keto esters were separated from the reduced hydroxy esters by chromatography, and the products were analyzed for levels of enantiomeric excess.Chiral shift reagents, Mosher esters, and optical rotation of the enantiomers of the alcohols were the criteria used to determine the optical integrity of the resolved alcohols after hydrolysis of the esters.Absolute sterochemistry was determined for the resolution products of all the substrates.Some rationale is advanced to account for the observed levels of enantiomeric excess and for the apparent diastereospecifity of the enzymatic resolution.The utility of this process as means of resolution of prochiral alcohols as well as an application of such resolution to the preparation of both enantiomers of a pyrrolizidine alkaloid synthon are indicated.
- Hudlicky, Tomas,Tsunoda, Toshiya,Gadamasetti, Kumar G.,Murry, Jerry A.,Keck, Gary E.
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p. 3619 - 3623
(2007/10/02)
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