Are there alternatives to Methyl (3R)-3-pyrrolidinecarboxylate (CAS: 428518-43-8) in synthesis?

Several alternatives can be considered in the synthesis of Methyl (3R)-3-pyrrolidinecarboxylate (CAS: 428518-43-8). Commonly, racemic 3-pyrrolidinecarboxylic acid can be used as a starting material, followed by resolution. Other isomers such as the (3S)-isomer can also be used, though the (3R)-isomer may be more preferred for certain applications. Citric acid derivatives and cyclic amides are other possible alternatives depending on the specific requirements of the synthesis.