L-theanine, (L-gamma-glutamylethyamide) is a non protein amino acid that occurs naturally in the tea plant (camellia sinensis). It present a similar chemical structure with glutamate and glutamine (fig1), which are the most important neurotransmitters related to memory. The theanine acts directly on the central nervous system and shows neuroprotective effects. Besides the graceful favorable physiological functions, a cooperative effect of theanine with several anti tumor agents has also been reported. theanine is able to cross the blood-brain barrier via leucine-perferring transport system. Firstly our work has been focused on production of L or D-Theanine and its derivatives L or D-5-N propylglutamine by an easy and efficient protocol assisted by microwaves irradiation. In the other hand we are engaged in synthesis of new 4-substituted Theanine derivatives by using (S)-pyroglutamate as starting compound. The Key step of this new strategy is a regional's and stereospecific alkylation on C4 induced by (S) configuration of C2, the high steric hindrance of protecting groups and the nature of alkylating reagent (schema 1 and 2). The (2S, 4R) configuration of C-bezylated theanine hs been confirmed by X Ray analysis of crystallized 2a intermediate compound (fig.2) and NMR spectroscopy of each derivatives (2a, 2b and 2c).