STUDIES ON THE RESOLUTION OF RACEMIC AMINO-ACID ESTERS BY A NEW RESOLVING AGENT R(-)THIAZOLIDINE-2-THIONE-4-CARBOXYLIC ACID

Amino acid esters were resolved by a new resolving agent R(-)thiazolid ine-2-thione-4-carboxylic acid [R(-)TTCA]. The optically active R(-)TT CA-amino acid ester salts 1a - 1f, [alpha](D)(20) = -30.40 degrees sim ilar to -42.70 degrees and optically active amino acid esters 2a - 2f (e.e.: 35.40% similar to 75.80%) were obtained, When 1a--1f reacted wi th aqueous NaOH, optically active amino acid esters 3a-3f (e. e: 39.50 % similar to 69.10%) were separated, The basicity of the amino group o f amino acid esters and the formation heats of ammonium salts of amino acid ester have been studied using semiempirical quantum chemistry PM 3 methods.