192512-81-5Relevant academic research and scientific papers
Lipase-mediated resolution of substituted 2-aryl-propanols: Application to the enantioselective synthesis of phenolic sesquiterpenes
Serra, Stefano
, p. 619 - 628 (2011/07/08)
A comprehensive study of the lipase-mediated resolution of substituted 2-aryl-propanols is reported. The latter alcohols were submitted to the irreversible acetylation catalyzed either by PPL, CRL, or lipase PS. The enantioselectivity of these transformations was dependent on the type of lipase used. The type of substituents and particularly their position on the aromatic ring strongly affected the selectivity of the reaction. The experiments described prove that PPL is the more versatile lipase catalyzing the acetylation with an enantiomeric ratio (E) value that ranges from 1 up to 144, depending on the substrate used. Conversely, the same transformations were catalyzed by CRL and lipase PS with an enantiomeric ratio value, which is always less than 5. The remarkable behavior of PPL was exploited in the large scale resolution of some substituted 2-aryl-propanols whose enantiomeric forms are relevant building blocks in the enantioselective synthesis of phenolic sesquiterpenes. By these means, the synthesis of (S)-turmeronol B and the formal syntheses of (R)-curcumene, (R)-curcuphenol, (R)-xanthorrhizol, and (R)-curcuhydroquinone were accomplished.
Copper hydride catalyzed enantioselective conjugate reduction of unsaturated nitriles
Lee, Daehyung,Yang, Youngmin,Yun, Jaesook
, p. 2233 - 2235 (2008/03/28)
α,β-Unsaturated nitriles were reduced with high levels of enantioselectivity via copper hydride catalysis. In this procedure, bench-top stable copper(II) acetate and Josiphos ligand are used as the chiral catalyst and an inexpensive hydrosilane, polymethy
Highly enantioselective conjugate reduction of β,β-disubstituted α,β-unsaturated nitriles
Lee, Daehyung,Kim, Daesung,Yun, Jaesook
, p. 2785 - 2787 (2008/02/04)
(Chemical Equation Presented) Easy access: The highly enantioselective conjugate reduction of α,β-unsaturated nitriles is achieved by employing bench-top stable copper(II) acetate and josiphos (L) as the ligand in the presence of polymethylhydrosiloxane (
Synthesis of (R)-ar-turmerone and its conversion to (R)-ar-himachalene, a pheromone component of the flea beetle: (R)-ar-himachalene is dextrorotatory in hexane, while levorotatory in chloroform
Mori, Kenji
, p. 685 - 692 (2007/10/03)
(R)-ar-Turmerone was synthesized from (4-methylphenyl)acetic acid by employing Evans asymmetric alkylation as the key step. (R)-ar-Turmerone was converted to (R)-ar-himachalene, which was dextrorotatory in hexane while levorotatory in chloroform. Enantiomerically impure (75% ee) (R)-3-(4-methylphenyl)butanoic acid crystallized more readily than the enantiomerically pure one.
Organic synthesis in pheromone science
Mori, Kenji
, p. 1023 - 1047 (2007/10/03)
Examples are given to illustrate the use of chemical and/or enzymatic asymmetric reactions in the synthesis of the new pheromones of the broad-horned flour beetle, flea beetle, currant stem girdler and Colorado potato beetle. The relationships between ste
New asymmetric construction of the benzylic quaternary stereogenic centre: An enantiocontrolled access to (-)-α-cuparenone
Kosaka, Takamitsu,Bando, Toshikazu,Shishido, Kozo
, p. 1167 - 1168 (2007/10/03)
An efficient and enantiocontrolled formal total synthesis of (-)-α-cuparenone has been accomplished by employing a new asymmetric construction methodology for formation of the benzylic quaternary stereogenic centre.
