73698-06-3

Upstream product

• 6405-71-6 (-)-(1R)-endo-2-Bornyl-phenylglyoxylat 
• 926-62-5 isobutylmagnesium bromide 
• 132314-76-2 (S)-2-hydroxy-2-phenyl-4-methyl-4-pentenoic acid 
• 51667-82-4 2-Hydroxy-4-methyl-2-phenyl-pentanoic acid (1R,2S,5R)-2-isopropyl-5-methyl-cyclohexyl ester 
• 51667-82-4 phenyl-2 hydroxy-2 methyl-4 pentanoate de (-) menthyle 
• 97690-15-8 (S)-2-hydroxy-2-phenyl-4-methylpentanoic acid methyl ester 
• 15206-55-0 methyl 2-oxo-2-phenylacetate 
• 611-73-4 Benzoylformic acid 
• 20229-41-8 l-menthyl phenylglyoxylate 
• 141652-48-4 <(1R,2R)-2-phenoxycyclohex-1-yl> phenylglyoxalate 
• 177981-47-4 (1R,2R)-2-nitroxycyclohexyl phenylglyoxylate 

Relevant academic research and scientific papers

Isomannide and isosorbide as new chiral auxiliaries for the stereoselective synthesis of tertiary α-hydroxy acids

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

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

(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

(1R,2R)-2-phenoxycyclohexan-1-ol is used as a chiral auxiliary for the preparation of α-hydroxy acids in high optical purities.

PLE catalyzed hydrolyses of α-substituted α-hydroxy esters: The influence of the substituents

The enzymatic hydrolyses of a variety of α-substituted mandelic and lactic esters using pig liver esterase (PLE) have been investigated. High to moderate enantioselectivity was found for various α-substituted mandelic esters, whereas PLE showed low to no enantioselectivity for α-substituted lactic esters. We observed that the enantioselectivity of PLE depends strongly on the length and nature of the substituent at the α-position. Some sequences for an active site model of PLE are discussed.

SYNTHESE D'α-HYDROXYACIDES OPTIQUEMENT ACTIFS PAR ADDITION D'ORGANOZINCIQUES SUR LE PHENYLGLYOXALATE DE (-) MENTHYLE

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

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

Asymmetric Synthesis Using Chiral Lithium Alkoxytrialkylaluminates: Obtention of (2S)-2-Hydroxy-2-phenyl-4-methylpentanoic Acid with 85percent Optical Purity

The chiral reagent prepared by mixing equimolecular amounts of triisobutylaluminium and lithium alcoholate of (+)-Darvon alcohol reacts readily in hexane solvent with methyl phenylglyoxylate to give the expected α-isobutyl α-hydroxy ester in 95percent chemical yield with no significant reduction byproduct, and best optical yields are achieved at 0 deg C and high dilution (0.04 M) in hexane.Upon saponification of the ester, (2S)-2-hydroxy-2-phenyl-4-methylpropanoic acid is obtained in 85percent enantiomeric excess.Reacting the lithium alkoxytriethylaluminate and lithium alkoxytri-n-butylaluminate with the same α-keto ester provided confirmatory evidence for the influence of dilution on the extent of asymmetric induction.