24256-91-5Relevant academic research and scientific papers
HAUTS RENDEMENTS OPTIQUES OBTENUS DANS LA SYNTHESE D'α-ALKYLα-HYDROXYESTERS PAR REACTION D'ALKOXYTRIALKYLALUMINATES ENCOMBRES AVEC LE PHENYLGLYOXALATE DE MENTHYLE.
Deberly, A.,Boireau, G.,Abenhaim, D.
, p. 655 - 658 (1984)
Enantiomeric purities in alkylation of (+) and (-) menthyl esters of phenylglyoxilic acid by complexes derived from AlEt3 and the lithium salts of (+) and racemic Darvon alcohol are depending upon the only stereochemistry of the menthyl group in ester.These results suggest that the observed stereochemistry is to be related to the bulkiness of the organometallic reagent, which overcomes the asymetric induction due to the chiral center of the alkoxy moiety.Accordingly, use of complexes from AlEt3 and non chiral alcohols of increasing sizes leads to increasing stereoselectivity.
Sodium channel binding and anticonvulsant activities for the enantiomers of a bicyclic 2,4-oxazolidinedione and monocyclic models
Brouillette,Grunewald,Brown,DeLorey,Akhtar,Liang
, p. 1577 - 1580 (1989)
Racemic 7-phenyl-9,10-dioxo-1-aza-8-oxabicyclo[5.2.1]decane (1), a bicyclic 2,4-oxazolidinedione that we previously reported was a possible sodium channel anticonvulsant, was resolved into its enantiomeric forms, the absolute configurations were determined, and the stereoisomers were evaluated for relative sodium channel binding and whole animal anticonvulsant activities. Similar studies were carried out with two monocyclic models, 5-ethyl-5-phenyl-2,4-oxazolidinedione (2) and 5-ethyl-3-methyl-5-phyenyl-2,4-oxazolidinedione (3). None of these isomers exhibited stereoselective effects in the sodium channel assay, and only modest enantioselectivities were observed for 2 and 3 in the anticonvulsant assays. (R)-(-)-1 was, however, 4 times more toxic than (S)-(+)-1 in the rotorod test, and due to its larger protective index, (S)-(+)-1 exhibited greater therapeutic potential than either (R)-(-)-1 or racemic 1.
Formal [3+2]-cycloaddition of ketenes and oxaziridines catalyzed by chiral lewis bases: Enantioselective synthesis of oxazolin-4-ones
Shao, Pan-Lin,Chen, Xiang-Yu,Ye, Song
supporting information; experimental part, p. 8412 - 8416 (2011/02/25)
Choose the right cat.: A highly enantioselective synthesis of oxazolin-4-ones by the formal [3+2]-cycloaddition of ketenes and a racemic oxaziridines has been developed (see scheme; cat.=N-heterocyclic carbenes for disubstituted ketenes or cinchona alkaloids for monosubstituted ketenes, Ts=4-toluenesulfonyl).
Enantioselective synthesis of either enantiomer of α-alkyl-α- hydroxy-α-phenylacetic acids using chiral auxiliaries
Perez-Estrada, Salvador,Lagunas-Rivera, Selene,Vargas-Diaz, Maria Elena,Velazquez-Ponce, Pedro,Joseph-Nathan, Pedro,Zepeda, L. Gerardo
, p. 1837 - 1843 (2007/10/03)
The enantioselective synthesis of either enantiomer of α-alkyl- α-hydroxy-α-phenylacetic acids was achieved by using 2-acyloxathianes 1a-c and the mixed acyl-S,O-acetals 7 and 8 as chiral auxiliaries, which can straightforwardly be prepared from (1R)-(-)-myrtenal. This procedure allowed the preparation of the title compounds in >95% enantiomeric excess (ee).
Isomannide and isosorbide as new chiral auxiliaries for the stereoselective synthesis of tertiary α-hydroxy acids
Loupy, André,Monteux, Daphné A
, p. 1541 - 1549 (2007/10/03)
Isomannide and isosorbide are selectively protected to provide new chiral auxiliaries suitable for the preparation of enantiopure tertiary α-hydroxy acids. Diastereoselective additions of organozinc reagents on the derived phenylglyoxylates afford the desired α-hydroxy acids with 60-99% ee after saponification. Both absolute configurations of the α-hydroxy acids can be accessed, by adapted choice of either the starting diol or the protecting group.
(1R, 2R)-2-nitroxycyclohexan-1-ol: First example of a cyclohexyl based chiral auxiliary with nitroxy function as diastereoface discriminating group
Basavaiah, Deevi,Pandiaraju, Subramanian,Bakthadoss, Manickam,Muthukumaran, Kannan
, p. 997 - 1000 (2007/10/03)
Application of nitroxy substituent as diastereoface discriminating group in a cyclohexyl based chiral auxiliary has been described.Copyright
New cyclohexyl-based chiral auxiliaries: Enantioselective synthesis of α-hydroxy acids
Basavaiah, Deevi,Krishna, Peddinti Rama
, p. 12169 - 12178 (2007/10/02)
(1R,2R)-2-(4-tert-butylphenoxy) cyclohexan-1-ol (5) and (1R,2R)-2-(4-phenylphenoxy) cyclohexan-1-ol (6) have been used for the first time as chiral auxiliaries. Addition of alkylzinc chlorides to the corresponding glyoxylates 5a, 6a, after hydrolysis, provided (R)-α-hydroxy acids in high optical purities.
Novel Steroidal Chiral Auxiliaries: Enantioselective Synthesis of Chiral α-Hydroxy Acids
Huang, Deeng-Lih,Draper, Richard W.
, p. 661 - 662 (2007/10/02)
The synthesis is reported of three novel steroidal chiral auxiliaries (4) which were used to generate an α-hydroxy acid in high optical purity (90-98percent ee).
trans-2-phenoxycyclohexan-1-ol as new chiral auxiliary: Synthesis of chiral α-hydroxy acids
Basavaiah,Bharathi,Krishna
, p. 941 - 947 (2007/10/02)
(1R,2R)-2-phenoxycyclohexan-1-ol is used as a chiral auxiliary for the preparation of α-hydroxy acids in high optical purities.
SYNTHESE D'α-HYDROXYACIDES OPTIQUEMENT ACTIFS PAR ADDITION D'ORGANOZINCIQUES SUR LE PHENYLGLYOXALATE DE (-) MENTHYLE
Boireau, G.,Deberly, A.,Abenhaim, D.
, p. 5837 - 5844 (2007/10/02)
Organozinc compounds readily obtained in situ from Grignard reagents and solutions of ZnCl2 or ZnBr2 in diethylether or THF add selectively to the keto group of (-) menthyl phenylglyoxalate.A variety of α-substituted mandelic acids o
