- Diastereoisomeric salt formation and enzyme-catalyzed kinetic resolution as complementary methods for the chiral separation of cis-/trans-enantiomers of 3-aminocyclohexanol
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This contribution demonstrates the preparative-scale synthesis of (1S,3S)-3-aminocyclohexanol by either enzymatic kinetic resolution of Cbz-protected 3-aminocyclohexanols or direct diastereoisomeric salt formation with (R)-mandelic acid. The salt formation demonstrates how a single enantiomer, (1S,3S)-3-aminocyclohexanol (R)-mandelate, can be effectively isolated from the cis/trans racemic mixture and subsequently converted to the free amine, (1S,3S)-3-aminocyclohexanol, by ion-exchange chromatography. We have also demonstrated how the other three enantiomers of 3-aminocyclohexanol can be prepared by either diastereoisomeric salt formation or enzymatic kinetic resolution.
- Brocklehurst, Cara E.,Laumen, Kurt,La Vecchia, Luigi,Voegtle, Markus,Shaw, Duncan
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experimental part
p. 294 - 300
(2011/10/02)
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- Resolution of trans-3-aminocyclohexanol
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(R,R)- and (S,S)-trans-3-Aminocyclohexanol were prepared via an enzymatic resolution of (±)-trans-1-acetoxy-3-benzylamido-cyclohexane with >95% enantiomeric excess.
- Bernardelli, Patrick,Bladon, Michael,Lorthiois, Edwige,Manage, Ajith C.,Vergne, Fabrice,Wrigglesworth, Roger
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p. 1451 - 1455
(2007/10/03)
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- Resolution of N-protected cis- and trans-3-aminocyclohexanols via lipase-catalyzed enantioselective acylation in organic media
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The enzymatic acylation of N-protected cis-and trans-1,3-aminocyclohexanols using lipases in organic solvents is described. By modifying certain reaction parameters such as the solvent, the lipase and the N-protecting group, it is possible to achieve high enantioselectivities and to obtain enantiomerically pure 3-aminocyclohexanols. The influence of the N-protecting group and the conformation of the substrate on the reaction rate was also studied.
- Levy, Laura M.,De Gonzalo, Gonzalo,Gotor, Vicente
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p. 2051 - 2056
(2007/10/03)
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- Reactions of 1-acylamino-1-(trimethylsiloxy)alkanes: Versatile precursors to acylimines
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1-Acylamino-1-(trimethylsiloxy)alkanes react with carbon and heteroatom nucleophiles to give the corresponding 1-substituted-1-acylaminoalkanes. The 1-acylamino-1-(trimethylsiloxy)alkanes can also give rise to enamides, and by this route the mild antibiotic tuberin, and the isomeric (Z)-tuberin have been prepared. A further example of their reactions is illustrated with the acid-catalysed intramolecular cyclisation onto a carbon-carbon double bond. These transformations show that 1-acylamino-1-(trimethylsiloxy)alkanes are versatile precursors to synthetically useful acylimines.
- Johnson, A. Peter,Luke, Richard W. A.,Boa, Andrew N.
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p. 895 - 905
(2007/10/03)
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- Convenient Procedure for the Reduction of β-Enamino Ketones: Synthesis of γ-Amino Alcohols and Tetrahydro-1,3-oxazines
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γ-Amino alcohols 3 can be easily synthesized in very good yields by reduction of enaminones 1 with Na in PrOH-tetrahydrofuran.The reaction is fast, easy to perform, inexpensive and the easily accesible starting materials provide a convenient entry to γ-amino alcohols.The relative configuration assignment of the diastereomeric γ-amino alcohols obtained has been established by 1H and 13C NMR studies and unequivocally assigned by their cyclic tetrahydro-1,3-oxazine derivatives 4.
- Bartoli, Giuseppe,Cimarelli, Cristina,Palmieri, Gianni
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p. 537 - 544
(2007/10/02)
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