Synthesis of 4-thiazolidineacetic acids and β-homopenicillamine

Article abstract of DOI:10.1055/s-1991-26505

4-Thiazolidineacetic acids 2, previously unknown homologs of the intensively examined thiazolidine-4-carboxylic acids, were readily prepared by addition of malonic acid to the azomethine group of various 2,5-dihydro-1,3-thiazoles 1, followed by decarboxylation at room temperature. Hydrolysis of 2,2,5,5-tetramethyl-4-thiazolidineacetic acid (2e) lead to β-homopenicillamine 3, a new homolog of the phamacologically interesting penicillamine, and its thiolactone hydrochloride 4.