title: Unsaturated syn- and anti-1,2-amino alcohols by cyclization of allylic bis-trichloroacetimidates. stereoselectivity dependence on substrate configuration.
abstract: Disubstituted allylic bis-imidates undergo Lewis acid catalyzed or spontaneous cyclization to oxazolines, which are precursors of unsaturated amino alcohols. Stereoselectivity of the cyclization is mainly determined by the substrate configuration. Highly selective cis-oxazoline formation is achieved starting from anti-E-bis-imidates while trans-oxazoline predominantly forms from anti-Z-bis-imidates. On the basis of DFT calculations, the stereoselectivity trends can be explained by the formation of the energetically most stable carbenium ion conformation, followed by the cyclization via most favorable bond rotations.
authors.affiliation: Latvian Institute of Organic Synthesis , Aizkraukles 21, Riga LV-1006, Latvia.
authors.forename: Liene
authors.initials: L
authors.lastname: Grigorjeva
authors.forename: Artis
authors.initials: A
authors.lastname: Kinens
authors.forename: Aigars
authors.initials: A
authors.lastname: Jirgensons
mesh_terms: D000081:Acetamides / Q000737:chemistry*; D000605:Amino Alcohols / Q000737:chemistry*; D062845:Chloroacetates / Q000737:chemistry*; D003500:Cyclization; D008968:Molecular Conformation; D010080:Oxazoles / Q000737:chemistry*; D011789:Quantum Theory; D013237:Stereoisomerism
chemical_list: D000081:Acetamides; D000605:Amino Alcohols; D062845:Chloroacetates; D010080:Oxazoles; C009528:trichloroacetamide