title: Concise, stereoselective route to the four diastereoisomers of 4-methylproline.
abstract: The full stereochemical characterization of 4-methylproline, a rare amino acid found in a number of peptidic secondary metabolites, has often been hindered by long reaction sequences or low stereoselectivity in the synthesis leading to reference samples. The preparation of the four diastereoisomers of 4-methylproline by a concise and stereoselective route is presented and features a six-step route with late-stage stereodivergence, good stereoselectivity for both cis- and trans-series (75% and 88% de, respectively), and good overall yields (cumulative yields of 30-40%). Additional data on the Marfey's derivatives of the stereoisomers are also presented.
authors.affiliation: Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
authors.forename: Annabel C
authors.initials: AC
authors.lastname: Murphy
authors.forename: Maya I
authors.initials: MI
authors.lastname: Mitova
authors.forename: John W
authors.initials: JW
authors.lastname: Blunt
authors.forename: Murray H G
authors.initials: MH
authors.lastname: Munro
mesh_terms: D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D011392:Proline / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: C474411:4-methylproline; D011392:Proline