title: Samarium diiodide promoted generation and asymmetric hydroxyalkylation of N,O-diprotected (3S)-3-pyrrolidinol 2-carbanions.
abstract: The N,O-diprotected chiral nonracemic 2-pyridyl 3-pyrrolidinol-2-yl sulfide 5a undergoes efficient SmI(2) mediated reduction to give the N,O-diprotected 3-pyrrolidinol 2-carbanion intermediate D, which reacted under Barbier-type conditions with ketones and aldehydes to afford the protected N-alpha-hydroxyalkyl-3-pyrrolidines 10b-h with excellent diastereoselectivity at the newly formed chiral center in the pyrrolidine ring. Application of the present method led to the formal asymmetric syntheses of (2R,3S)-2-hydroxymethyl-3-pyrrolidinol (2) and (2S,3S)-3-hydroxyproline (12). [reaction: see text]
authors.affiliation: Department of Chemistry and The Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, P. R. China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Zheng
authors.forename: Chen-Guo
authors.initials: CG
authors.lastname: Feng
authors.forename: Jian-Liang
authors.initials: JL
authors.lastname: Ye
authors.forename: Pei-Qiang
authors.initials: PQ
authors.lastname: Huang
mesh_terms: D000838:Anions; D002219:Carbamates; D006900:Hydroxylation; D007454:Iodides; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D011759:Pyrrolidines / Q000138:chemical synthesis*; D012493:Samarium
chemical_list: D000838:Anions; D002219:Carbamates; D007454:Iodides; D011759:Pyrrolidines; D012493:Samarium; C409809:samarium diiodide; C059692:phenylcarbamic acid