(2S,4S)-1-(9-Fluorenylmethyloxycarbonyl)-4-tritylmercapto-pyrrolidine-2-carboxylic acid

4-Mercaptoproline, a hybrid, or chimeric amino acid which combines the properties of proline and homocysteine. It can be used for disulfide bridge formation with defined sterical orientation. This building block has also been used for multiple controlled native chemical ligations. References: Multiple Binding Modes for the Receptor-Bound Conformations of Cyclic AII Agonists; Krystina Plucinska, Takahiro Kataoka, Mitsuaki Yodo, Wayne L. Cody, J. X. He, Christine Humblet, G. H. Lu, Elizabeth Lunney, Terry C. Major, Robert L. Panek, Pamela Schelkun, Richard Skeean, and Garland R. Marshall; J. Med. Chem. 1998; 36: 1902-1913. Novel Cyclic Analogs of Angiotensin II with Cyclization between Positions 5 and 7: Conformational and Biological Implications; Wei-Jun Zhang, Gregory V. Nikiforovich, Jacqueline Pérodin, Darren E. Richard, Emanuel Escher, and Garland R. Marshall, J. Med. Chem. 1996; 39: 2738-2744. Dual Kinetically Controlled Native Chemical Ligation Using a Combination of Sulfanylproline and Sulfanylethylanilide Peptide; Hao Ding, Akira Shigenaga, Kohei Sato, Ko Morishita, and Akira Otaka; Org. Lett. 2011; 13(20): 5588-5591. DOI 10.1021/ol202316v.