196302-06-4Relevant academic research and scientific papers
Robust enzymatic resolution of 3-fluoromandelic acid with lipase PS supported on celite
Mendiola, Javier,Garcia-Cerrada, Susana,De Frutos, Oscar,De La Puente, Maria Luz
experimental part, p. 1312 - 1316 (2012/10/18)
The resolution of different mandelic acids using the lipase PS Amano SD enzyme is described. By supporting the lyophilized enzyme over Celite, both the activity and the stability of lipase PS in organic media were significantly improved, enabling the robust resolution scale-up of 3-fluoromandelic acid. The methodology was extended to produce a range of optically pure (R)-mandelic acids, avoiding tedious extractions or chromatography.
Hydrogen-bonding sheets in crystals for chirality recognition: synthesis and application of (2S,3S)-2,3-dihydroxy- and (2S,3S)-2,3-dibenzyloxy-1,4-bis(hydroxyamino)butanes
Kobayashi, Yuka,Kokubo, Yasushi,Aisaka, Takamitsu,Saigo, Kazuhiko
scheme or table, p. 2536 - 2541 (2009/04/11)
Two enantiopure bis(hydroxyamino) compounds were successfully prepared from dialkyl tartrate by a chiral-pool method and applied as basic resolving agents in the enantioseparation of 2-arylpropanoic acids and arylglycolic acids. (2S,3S)-2,3-Dihydroxy-1,4-bis(hydroxyamino)butane (2S,3S)-1a could moderately recognize the chirality of the 2-arylpropanoic acids, while (2S,3S)-2,3-dibenzyloxy-1,4-bis(hydroxyamino)butane (2S,3S)-1b could not due to the low crystallinity of both the corresponding diastereomeric salts. On the other hand, (2S,3S)-1b showed a similar chirality-recognition ability for the arylglycolic acids. The ability of (2S,3S)-1b was different from those generally observed for widely used primary amine-type resolving agents with regard to the relationship between the resolution efficiency and the similarity in the relative molecular length of a resolving agent and a target racemate. The X-ray crystallographic analyses of the less-soluble diastereomeric salts revealed that in the salts (2S,3S)-1a formed a supramolecular sheet, of which the distance was variable to make the resultant dissymmetric space fit to the shape of the target acids, and that (2S,3S)-1b was constructed from a robust supramolecular sheet, consisting of hydrogen-bonding 21 columns, with the participation of the hydroxy group of the arylglycolic acids. These X-ray crystallographic analyses also suggested that for the formation of a supramolecular sheet, the coexistence of two hydroxyamino groups is essential.
METHOD FOR PRODUCING SUBSTITUTED SHIRAL DIOLS AND DIOL-ANALOGOUS DERIVATIVES
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Page/Page column 16, (2008/06/13)
The invention relates to a method for producing substituted shiral diols and the derivatives thereof of formula (I), wherein R is H or possibly substituted C5-C20-aryl-, C5-C20-heterocycle or C1-C20 alkyl radical or R1is possibly substituted C5-C20-aryl, C5-C20-heterocycle or C1-C20 alkyl; R2 is H or C1-C20 alkyl, C3-C7-heterocycle, silyl, C5-C20-aryl, C5-C20-arylsulphonyl or C1-C20-alkylsulphonyl; R3 is H or an O protection group; and X is oxygen, sulphur, nitrogen or phosphorus. The inventive method consists a) in transforming hydroxycarboxylic acid of formula (II), wherein R4 id H or C1-C6 alkyl provided with a link of the O protection group into a component of formula (III), wherein R3 is the O protection group; b) in reducing said acid into a compound of formula (IV) with alkali boron-or aluminium hydride; c) possibly activating and exchanging one oxygen atom against a radical containing one sulphur, nitrogen or phosphorus atom; or d) possibly transforming said acid with alkylation or arylation reagents into a compound of formula (V), wherein R′2 is possibly substituted C1-C20 alkyl-, C3-C7-heterocyclic-, silyl-, C5-C20-aryl-, C5-C20-arylsulphonyl or C1-C20- alkylsulphonyl and R3 is O protection group,
