Arylglyoxylic acids

Simple extensions of this method involve the use of arylglyoxylic acids (e.g., phenylglyoxylic acid, PhCOCOjH) and a variety of pyruvic acids (RCH2COCO2H) and a-keto acids or their esters (Scheme 1). ... 

Enantioface differentiating reduction of arylglyoxylic acids can be performed with NaBH4 in aqueous buffer media using a modified CD, 6-deoxy-6-amino-p-cyclodextrin [78]. The reaction proceeds with high yields but the arylglycolic acids obtained had low ee. The use of water-soluble chiral paracyclophanes does not increase the enantioselectivity of the reaction. 

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