Abstract
A series of new 4-(arylmethylene)-3-isochromanones 1-17 has been prepared by base-catalyzed Knoevenagel condensations. Stereochemical and conformational analyses were performed by 1H and 13C NMR methods, and X-ray crystallography was used to complement the configurational assignment for a representative product. The reaction generally yields the (E) isomer, but the isomeric composition of the products was influenced by the aromatic aldehyde and usually governed by the stability of the products. Several aldehydes exclusively afforded the (Z) isomer, due to intramolecular steric/electronic interactions reflected in the increased stability of the product. The condensation performed with ortho-hydroxyarenecarbaldehydes furnished the unexpected 3-arylcoumarins or 3-arylbenzocoumarins.
Original language | English |
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Pages (from-to) | 2996-3003 |
Number of pages | 8 |
Journal | European Journal of Organic Chemistry |
Issue number | 17 |
DOIs | |
State | Published - Sep 2002 |
Keywords
- Heterocycles
- Lactones
- Molecular modeling
- NMR spectroscopy
- X-ray diffraction