Jagdish Prasad, Pradeep K. Golay and Sharad K. Panday* Pages 248 - 253 ( 6 )
Background: 4-substituted pyroglutamates have found use in the synthesis of ACE inhibitors e.g. Fosinopril, conformationally constrained peptides as well as bioactive natural products. Such versatile applications associated with 4-substituted Pyroglutamates encouraged researchers to study the Lienolate derived alkylation of pyroglutamate with electrophiles. Though several reports are available on Li-enolate derived reactions of pyroglutamates with electrophiles, but sodium-enolate derived reactions of pyroglutamate with electrophiles have not been investigated, and that prompted us to study the behaviour of sodium enolate derived reactions of N-protected pyroglutamates with electrophiles.
Results and Discussion: Herein we have reported our studies on the sodium enolate derived reactions of N-protected pyroglutamate with electrophiles, where N-Boc-(2S)-menthyl pyroglutamate on reaction with various electrophiles in the presence of Sodium hydride afforded 4-substituted pyroglutamates while under similar conditions N-benzyl-(2S)-menthyl pyroglutamate afforded exclusively 2-substituted pyroglutamates.
Conclusion:We have successfully accomplished sodium enolate derived alkylation/aldol reaction on NBoc- (2S)-menthyl and N-Benzyl-(2S)-menthyl pyroglutamate with an objective to synthesize 4– substituted pyroglutamates as well as 2-substituted pyroglutamates. These 4-substituted pyroglutamates and 2-substituted pyroglutamates have potential to serve as intermediate for the synthesis of bioactive natural products, ACE inhibitors and conformationally restricted peptide analogs.
Sodium enolate derived reactions, aldol reaction, alkylation, 4- substituted pyroglutamates, 2- substituted pyroglutamates.
Department of Applied Chemistry, Faculty of Engineering and Technology, M.J.P. Rohilkhand University, Bareilly, Uttar Pradesh 243006, Department of Applied Chemistry, Faculty of Engineering and Technology, M.J.P. Rohilkhand University, Bareilly, Uttar Pradesh 243006, Department of Applied Chemistry, Faculty of Engineering and Technology, M.J.P. Rohilkhand University, Bareilly, Uttar Pradesh 243006