title: Asymmetric syntheses of (-)-3-epi-Fagomine, (2R,3S,4R)-dihydroxypipecolic acid, and several polyhydroxylated homopipecolic acids.
abstract: A range of enantiopure polyhydroxylated piperidines, including (2R,3S,4R)-dihydroxypipecolic acid, (-)-3-epi-fagomine, (2S,3S,4R)-dihydroxyhomopipecolic acid, (2S,3R,4R)-dihydroxyhomopipecolic acid, and two trihydroxy-substituted homopipecolic acids, have been prepared using diastereoselective olefinic oxidations of a range of enantiopure tetrahydropyridines as the key step. The requisite substrates were readily prepared from tert-butyl sorbate using our diastereoselective hydroamination or aminohydroxylation protocols followed by ring-closing metathesis. After diastereoselective olefinic oxidation of the resultant enantiopure tetrahydropyridines and deprotection, enantiopure polyhydroxylated piperidines were isolated as single diastereoisomers (>99:1 dr) in good overall yield.
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford , Mansfield Road, Oxford OX1 3TA, U.K.
authors.forename: Kristína
authors.initials: K
authors.lastname: Csatayová
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Davies
authors.forename: Ai M
authors.initials: AM
authors.lastname: Fletcher
authors.forename: J Gair
authors.initials: JG
authors.lastname: Ford
authors.forename: David J
authors.initials: DJ
authors.lastname: Klauber
authors.forename: Paul M
authors.initials: PM
authors.lastname: Roberts
authors.forename: James E
authors.initials: JE
authors.lastname: Thomson
mesh_terms: D050112:Imino Pyranoses / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010875:Pipecolic Acids / Q000737:chemistry*; D010880:Piperidines / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D050112:Imino Pyranoses; D010875:Pipecolic Acids; D010880:Piperidines; C105643:fagomine; C031345:pipecolic acid