title: Highly diastereoselective and stereodivergent dihydroxylations of acyclic allylic amines: application to the asymmetric synthesis of 3,6-dideoxy-3-amino-L-talose.
abstract: Aminohydroxylation of tert-butyl sorbate [tert-butyl (E,E)-hexa-2,4-dienoate] using enantiopure lithium (R)-N-benzyl-N-(α-methylbenzyl)amide and (-)-camphorsulfonyloxaziridine gives tert-butyl (R,R,R,E)-2-hydroxy-3-[N-benzyl-N-(α-methylbenzyl)amino]hex-4-enoate in >99:1 dr. Subsequent dihydroxylation under Upjohn conditions (OsO(4)/NMO) gives tert-butyl (2R,3R,4S,5S,αR)-2,4,5-trihydroxy-3-[N-benzyl-N-(α-methylbenzyl)amino]hexanoate (in 95:5 dr) while dihydroxylation under Donohoe conditions (OsO(4)/TMEDA) proceeds with antipodal diastereofacial selectivity to give the (R,R,R,R,R)-diastereoisomer (in 95:5 dr). The amino triols resulting from these dihydroxylation reactions are useful for further elaboration, as demonstrated by the asymmetric synthesis of 3,6-dideoxy-3-amino-L-talose.
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, UK.
authors.forename: Kristína
authors.initials: K
authors.lastname: Csatayová
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Davies
authors.forename: James A
authors.initials: JA
authors.lastname: Lee
authors.forename: Paul M
authors.initials: PM
authors.lastname: Roberts
authors.forename: Angela J
authors.initials: AJ
authors.lastname: Russell
authors.forename: James E
authors.initials: JE
authors.lastname: Thomson
authors.forename: David L
authors.initials: DL
authors.lastname: Wilson
mesh_terms: D000588:Amines / Q000737:chemistry*; D000606:Amino Sugars / Q000138:chemical synthesis* / Q000737:chemistry; D008094:Lithium / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: C559229:3,6-dideoxy-3-amino-L-talose; D000588:Amines; D000606:Amino Sugars; D008094:Lithium