- Concise catalytic asymmetric total synthesis of biologically active tropane alkaloids
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A general strategy for the total asymmetric synthesis of valuable tropane alkaloids by catalytic stereoselective transformations is disclosed. The power of this approach is exemplified by the concise catalytic enantioselective total syntheses of (+)-methylecgonine, (-)-cocaine and (+)-cocaine as well as the first catalytic asymmetric total syntheses of a cocaine C-1 derivative and (+)-ferruginine starting from 5-oxo-protected-α,β-unsaturated enals using only two and three column chromatographic purification steps, respectively. Copyright
- Cordova, Armando,Lin, Shuangzheng,Tseggai, Abrehet
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p. 1363 - 1372
(2012/06/18)
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- Asymmetric total synthesis of (S)-(+)-cocaine and the first synthesis of cocaine C-1 analogs from N -sulfinyl β-amino ester ketals
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Sulfinimine-derived α,β-unsaturated pyrrolidine nitrones, on heating with Al(O-t-Bu)3, undergo a highly stereoselective intramolecular [3 + 2] cycloaddition to give tricyclic isoxazolidines, which are transformed in three-steps to give C-1 substituted cocaine analogs.
- Davis, Franklin A.,Theddu, Naresh,Edupuganti, Ram
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supporting information; experimental part
p. 4118 - 4121
(2010/11/17)
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- METHODS FOR PRODUCING HYDROXYALKYL TROPANE ESTERS
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This invention provides a method for preparing a hydroxyalkyl tropane ester, comprising: (a) contacting a tropane and 1,1'-carbonyldiimidazole to produce an activated tropane ester; (b) contacting the activated tropane ester with an excess of an alkanediol to form a reaction mixture; and (c) maintaining the reaction mixture at a temperature and for a sufficient time for the activated tropane ester to react with the alkanediol to form the corresponding hydroxyalkyl tropane ester. This method may be used to produce hydroxyalkyl derivatives of tropanes such as benzoylecgonine, ecgonine and ecgonidine.
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- Total synthesis of (+)-cocaine via desymmetrization of a meso-dialdehyde
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(Chemical Equation Presented) The total synthesis of (+)-cocaine is described. An extension of the recently reported proline catalyzed intramolecular enol-exo-aldol reaction to a meso-dialdehyde provided the tropane ring skeleton directly with good enanti
- Mans, Douglas M.,Pearson, William H.
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p. 3305 - 3308
(2007/10/03)
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- Enantiospecific Synthesis of Natural (-)-Cocaine and Unnatural (+)-Cocaine from D- And L-Glutamic Acid
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Natural (-)-cocaine and unnatural (+)-cocaine have been synthesized enantiospecifically from D-and L-glutamic acid, respectively. The axial-equatorial substitutents were introduced by a stereo-and regiospecific dipolar cycloaddition to the corresponding (1R,5S)- and (1S,5R)-N-BOC-nortropenes with (ethoxycarbonyl)formonitrile N-oxide. A sequence of subsequent stereochemically controlled transformations converted the fused isoxazoline to the requisite β-hydroxy ester. Synthesis of the key intermediate N-BOC-nortropenes involved construction of the 8-azabicyclo[3.2.1]octane framework by Dieckmann condensation of cis-5-substituted D- and L-proline esters. For comparison, (1R,5S)-N-BOC-nortropene also was derived by degradation from natural cocaine. The cis-5-substituted D- and L-proline esters were obtained by sulfide contraction and subsequent catalytic hydrogenation to induce stereospecifically the C-5 stereochemistry from D- and L-thiopyroglutamate, which in turn were prepared from D- and L-glutamic acids, respectively.
- Lin, Ronghui,Castells, Josep,Rapoport, Henry
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p. 4069 - 4078
(2007/10/03)
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- A PLE-based resolution of cocaine, pseudococaine, and 6-and 7-methoxylated cocaine analogues
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The enzymatic hydrolysis of racemic cocaine and cocaine analogues using pig liver esterase (PLE) is shown to afford a practical means for achieving their chemical resolution. This reaction was found to proceed not only with good enantioselectivity, but with an interesting chemoselectivity as well.
- Kozikowski,Simoni,Baraldi,Lampronti,Manfredini
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p. 441 - 444
(2007/10/03)
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