Abstract: A high-yielding enantioselective synthesis of the bioactive (S)—N-(5-chlorothiophene-2-sulfonyl)-?,?-diethylalaniol (7.b.2), a Notch-1-sparing ?-secretase inhibitor metabolite (with EC50=28 nM) effective in reduction of A? production in vivo, has been realized starting from readily available 3-pentanone. The key steps of the synthesis are proline-catalyzed ?-aminooxylation and ?-amination of aldehyde; the latter contributing an overall yield of 50-75% and 90-99% enantiomeric excess.

Abstract: A high-yielding enantioselective synthesis of the bioactive (S)—N-(5-chlorothiophene-2-sulfonyl)- ?,?-diethylalaniol (7.b.2), a Notch-1-sparing ?-secretase inhibitor metabolite (with EC50=28 nM) effective in reduction of A? production in vivo, has been realized starting from readily available 3-pentanone. The key steps of the synthesis are proline-catalyzed ?-aminooxylation and ?-amination of aldehyde; the latter contributing an overall yield of 50-75% and 90-99% enantiomeric excess.

Abstract: The present invention provides a commercially viable process for the preparation of highly pure and optically active L-(+)-lactic acid and S-(?)-methyl lactate, in high yield, obtained from esterification of aqueous crude lactic acid solution produced by sugar cane juice fermentation broth and methanol in continuous counter current trickle phase approach or in continuous counter current bubble column manner, using stabilizers and the methyl lactate so obtained is recovered and followed by purification of reasonably pure methyl lactate using reagent mixture such as sodium bi-carbonate, mono-ethanolamine or di-ethanolamine, urea or sodium-bicarbonate, mono-ethanolamine or di-ethanolamine, thiourea to reduce the impurity of dimethyl ester of dicarboxylic such as dimethyl oxalate or di-methyl succinate or methyl ester of mono-carboxylic acid such as methyl pyruvate present as an impurity, so as to get highly pure S-(?)-methyl lactate followed by hydrolyzing highly pure S-(?)-methyl lactate using highly pure lacti

Abstract: The present invention provides a commercially viable process for the preparation of highly pure and optically active L-(+)-lactic acid and S-(?)-methyl lactate, in high yield, obtained from esterification of aqueous crude lactic acid solution produced by sugar cane juice fermentation broth and methanol in continuous counter current trickle phase approach or in continuous counter current bubble column manner, using stabilizers and the methyl lactate so obtained is recovered and followed by purification of reasonably pure methyl lactate using reagent mixture such as sodium bi-carbonate, mono-ethanolamine or di-ethanolamine, urea or sodium-bicarbonate, mono-ethanolamine or di-ethanolamine, thiourea to reduce the impurity of dimethyl ester of dicarboxylic such as dimethyl oxalate or di-methyl succinate or methyl ester of mono-carboxylic acid such as methyl pyruvate present as an impurity, so as to get highly pure S-(?)-methyl lactate followed by hydrolyzing highly pure S-(?)-methyl lactate using highly pure lacti