73746-01-7Relevant academic research and scientific papers
Chiral linker. Part 4: Diastereoselective addition of RZnX to α-keto esters using m-hydrobenzoin derived chiral auxiliaries in solution and on solid support and their application in the stereoselective synthesis of frontalin
Schuster, Christian,Knollmueller, Max,Gaertner, Peter
, p. 2430 - 2441 (2007/10/03)
Two recently reported, m-hydrobenzoin derived open chain chiral auxiliaries, which were developed for application in either solution or immobilized on a solid support, were tested in the diastereoselective addition of RZnX to their corresponding phenylglyoxylates and pyruvates, respectively, resulting in diastereoisomeric excesses of up to >98% de. The optimized procedure was applied in the stereoselective synthesis of frontalin, the aggregation pheromone of pine bark beetles of the Dendroctonus family, by the use of both the solution phase and the polymer supported chiral auxiliary.
Stereoselective synthesis of α-alkyl-α-hydroxylphenylacetic acid. Part (I): Asymmetric alkylation of (S)-mandelic acid
Han, Xiang-Yu,Liu, He,Liu, Chun-He,Wu, Bo,Zhong, Bo-Hua,Liu, Ke-Liang
, p. 816 - 817 (2007/10/03)
An effective asymmetric synthesis of α-alkyl-α-hydroxyl phenyl acetic acid using benzaldehyde as steric hindrance agent has been accomplished by utilising the readily available and inexpensive chiral starting material, (S)-mandelic acid. The ee was determined by 1H NMR with Eu(hfc) 3 as shift reagent.
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.
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
ADDITION DIASTEREOSELECTIVE D'ORGANOZINCIQUES SUR LE PHENYLGLYOXALATE DE (-) MENTHYLE
Boireau, G.,Deberly, A.,Abenhaim, D.
, p. 2175 - 2176 (2007/10/02)
Organozinc compounds (from Grignard reagents and ZnCl2 or ZnBr2 in diethylether or THF) add selectively to the keto group of (-) menthyl phenylglyoxalate, to give α-substituted (-) menthyl mandelates in high yields and in most cases high levels of asymmet
