Preparation of m-Hydroxyphenyl-L- and D-Lactic Acids and Other Compounds Related to m-Tyrosine¹

Abstract

2-hIethyl-4-(3'-acetoxybenzal)-5-oxazolone was hydrolyzed to yield m-hydroxyphenylpyruvic acid, which was reduced to m-hydroxyphenyllactic acid. m-Hydroxyphenyllactic acid was resolved by fractional crystallization of the quinine salts. m-Hydroxymandelic acid, m-hydroxymandelic ethyl ester, and m-hydroxyphenylacetic acid nere prepared in good yields via m-hydroxymandelonitrile.

Amino acid oxidase‐catalysed resolution and Pictet–Spengler reaction towards chiral and rigid unnatural amino acids

“…The additional advantage of the D‐amino acid‐oxidase from T. variabilis is the strict enantioselectivity, very good stability and availability. This biocatalytic method is much more straightforward and convenient than other chemical procedures25, 26 and in addition allows the isolation of m‐hydroxyphenylpyruvate 27…”

An improved procedure for synthesis of DL-4-hydroxy-3-methoxymandelic acid (DL-""vanillyl""-mandelic acid, VMA)

“…The Denantiomorph of IV is one of the major me tabolite s of epinephrine and norepinep hrine found in normal human urine [1),1 but abnormally high concentrations of IV are found in th e urin e of patients havin g pheochromocytoma [2].…”

Novel, One-Pot Procedure for the Synthesis of 2-Arylethanol Derivatives

“…For example, a four-step procedure comprises Blanc chloromethylation, followed by substitution with cyanide, saponification, and reduction 4,5 to yield arylethanol derivatives. In another procedure an aromatic aldehyde is reacted with cyanide to afford an a-hydroxynitrile, which upon reductive hydrolysis 6,7 and subsequent reduction 8,9 leads to the desired arylethanol derivative.…”