(2S,4R)-4-Ammonio-5-oxopyrrolidine-2-carboxylate

Abstract

In the crystal structure of the title compound, C5H8N2O3, the mol­ecules exist in the zwitterionic form. The pyrrolidine ring adopts an envelope conformation with the unsubstituted endocyclic C atom situated at the flap. The other four endocyclic atoms are coplanar with the exocyclic carbonyl O atom, with an r.m.s. deviation from the mean plane of 0.06 Å. The carboxyl­ate substituent is located axially, while the ammonium group occupies an equatorial position. In the crystal structure, the mol­ecules are linked through N—H⋯O hydrogen bonds, forming a three-dimensional network.

A Global Review on Short Peptides: Frontiers and Perspectives

“…The synthesis of modified amino acids and short peptides is based on reactions of functional groups. An example of modified amino acids at α-carbon atom could be α-hydroxymethylvaline [ 128 ], while 4-aminopyroglutamic acid can serve as cyclized dipeptide unit [ 140 ].…”