Glyoxylate, glycine synthesis from

Addition of nucleophiles to electrophilic glycine templates has served as an excellent means of synthesis of a-amino acid derivatives [2c, 4—6]. In particular, imines derived from a-ethyl glyoxylate are excellent electrophiles for stereoselective construction of optically active molecules [32], This research and retrosyn-thetic analysis led us to believe that amine-catalyzed asymmetric Mannich-type additions of unmodified ketones to glyoxylate derived imines would be an attractive route for synthesis of y-keto-ce-amino acid derivatives [33], Initially, L-proline-catalyzed direct asymmetric Mannich reaction with acetone and N-PMP-protected a-ethyl glyoxylate was examined in different solvents. The Mannich-type reaction was effective in all solvents tested and the corresponding amino acid derivative was isolated in excellent yield and enantioselectivity (ee >95 %). Direct asymmetric Mannich-type additions with other ketones afford Mannich adducts in good yield and excellent regio-, diastereo- and enantioselectivity (Eq. 8). 

AGX1 Alanine glyoxylate aminotransferase, catalyzes the synthesis of glycine from glyoxylate, which is one of three pathways for glycine biosynthesis in yeast has similarity to mammalian and plant alanine glyoxylate aminotransferases... 

The synthesis of A/-acyl-a-chloroglycine and its use in the preparation of other a-substituted glycines has been described.N-Acylhemiaminals, prepared from glyoxylic acid and amides, carbamates, or ureas, can be converted into N-acyl-a-arylglycines by reaction with aromatic hydrocarbons in sulphuric acid. The same type of hemiaminals may be converted into N-acyl-y-keto-a-amino-acids by reactions with 1,3-dicarbonyl compounds again in the presence of concentrated sulphuric acid. °°... 

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