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Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
(2R,3R,5R)-2-
1Bijvoet Center for Biomolecular Research, Department of Crystal and Structural Chemistry, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands. d.d.ellis@chem.uu.nl.
Acta Crystallographica. Section C, Crystal Structure Communications
|September 15, 2000
Summary
This study reports the molecular structures of two chiral cyclohexanones derived from R-(-)-carvone. Crystal analyses confirmed their conformations, as spectroscopic methods like NMR and IR were insufficient to determine stereochemistry.
Area of Science:
- Organic Chemistry
- Crystallography
- Spectroscopy
Background:
- Chiral cyclohexanones are important structural motifs in organic chemistry.
- R-(-)-carvone serves as a versatile chiral precursor for synthesizing complex molecules.
- Understanding the conformational properties of these compounds is crucial for their applications.
Purpose of the Study:
- To elucidate the molecular structures and conformational properties of two novel chiral cyclohexanones derived from R-(-)-carvone.
- To investigate the limitations of spectroscopic techniques (NMR, IR) in determining the stereochemistry of these complex molecules.
- To utilize X-ray crystallography for unambiguous structural and conformational analysis.
Main Methods:
- Synthesis of two chiral cyclohexanone derivatives from R-(-)-carvone.
- Characterization using Nuclear Magnetic Resonance (NMR) and Infrared (IR) spectroscopy.
- Single-crystal X-ray diffraction analysis to determine molecular structures and conformations.
Main Results:
- The molecular structure of compound (I) (C(17)H(26)O(3)) revealed a chair conformation for the six-membered ring and a cis configuration for the fused furofuranyl substituent.
- Compound (II) (C(17)H(23)NO) exhibited a decalin core with one ring in a chair conformation and the other in a half-boat conformation.
- Spectroscopic data (NMR, IR) were unable to definitively establish the stereochemistry at all chiral centers.
Conclusions:
- X-ray crystallography provided definitive structural and conformational insights for both chiral cyclohexanones.
- The study highlights the complementary roles of spectroscopy and crystallography in characterizing complex organic molecules.
- Conformational analysis of these R-(-)-carvone derivatives offers valuable data for synthetic and medicinal chemistry endeavors.
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