title: Facile synthetic route to enantiopure unsymmetric cis-2,5-disubstituted pyrrolidines.
abstract: The (+/-)-cis-5-arylcarbamoyl-2-ethoxycarbonylpyrrolidines 6a-g were firstly synthesized in 53-64% yields by using meso-diethyl-2,5-dibromoadipate 3 and (S)-(-)-1-phenylethylamine in three steps. The diastereomeric mixture (S;2S,5R)-(-)-7 and (S;2R,5S)-(+)-8 were prepared by the Grignard reaction and separated by a flash column chromatography in 29 and 52% yields. The absolute configurations of (+)-8 was confirmed by X-ray crystallographic analysis and the enantiopure pyrrolidines (2S,5R)-(-)-9/(2R,5S)-(+)-9 and (2S,5R)-(-)-10/(2R,5S)-(+)-10 were obtained in good yields.
authors.affiliation: Department of Pharmacy, Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Ping-An
authors.initials: PA
authors.lastname: Wang
authors.forename: Zheng-Shuang
authors.initials: ZS
authors.lastname: Xu
authors.forename: Chun-Feng
authors.initials: CF
authors.lastname: Chen
authors.forename: Xu-Guang
authors.initials: XG
authors.lastname: Gao
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Sun
authors.forename: Sheng-Yong
authors.initials: SY
authors.lastname: Zhang
mesh_terms: D018360:Crystallography, X-Ray; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D011759:Pyrrolidines / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D011759:Pyrrolidines