The general procedure for the synthesis of (S)-2-methylproline and (R)-2-methylpyrrolidine-2-carboxylic acid from the compounds (CAS: 848488-83-5) is as follows: (R)-α-methylproline amide (0.40 g, 58% purity, 1.78 mmol) prepared in Reference Example 4 was added to a reaction flask with 6 M hydrochloric acid (2 mL) and stirred at 90°C for The reaction was carried out for 4 hours. Upon completion of the reaction, the product was analyzed by high performance liquid chromatography (HPLC) to confirm the presence of (R)-α-methylproline (204 mg, 1.58 mmol) in 90% yield and 89% ee optical purity.
