An Approach to 2,3-Diaminosuccinic Acid Derivatives—Synthesis of 2-Thioxo-1,3-Imidazolidines by a Mannich Reaction

Abstract

The article deals with a new synthesis of 2-thioxo-1,3-imidazolidine derivatives, masked 2,3-diaminosuccinic acids. The described procedure leads to the designed products by an intermolecular Mannich reaction between aldimine (ethyl iminoacetate) and enolates derived from 2-isothiocyanatocarboxylic esters. The prepared heterocyclic products having two stereogenic centers can be easily separated into cis- and trans- diastereoisomers. The reactivity of titanium(iv), lithium, and potassium enolates and the influence of ester groups on the yields and diastereoselectivities of the Mannich reactions are discussed.