Hydroxyl Substitutional Effect on Selective Synthesis of cis, trans Stilbenes and 3-Arylcoumarins Through Perkin Condensation

Abstract

The substitutional effect in the selective synthesis of cis, trans stilbenes and 3-arylcoumarins has been described. The regio- and geometrical selectivity for synthesis of stilbene derivatives under the Perkin strategy strongly depends on the presence or absence of hydroxyl group as well as their positions in the phenyl ring. As a result, practical synthetic strategies were established for preparing various natural stilbenes including combretastatin A-4, pterostilbene, and resveratrol with satisfactory yields (49.2–63.7%).

GRAPHICAL ABSTRACT

Keywords:

• 3-Arylcoumarins
• isomerization
• Perkin reaction
• polyphenolic stilbenes
• selectivity

ACKNOWLEDGMENTS

This project was supported by the Science and Technology Program of Guangdong Province, Strategic Cooperation Program between Guangdong Province and Chinese Academy of Sciences, and National Key Technology Research and Development Program, China (2003B31603, 2006B35604002, 2009B091300125 and 2007BAD82B02).

Notes

^a E-2,3-diarylcrylic acids were obtained as the sole products after single crystallization. All products were characterized by ¹H NMR, IR, and MS spectra.

^b Isolated yields.

Note. ND, not done.

^a Free hydroxyl groups in reactants have been acetylated during the reaction to give 4, followed by hydrolysis to give 7. All products were characterized by ¹H NMR, IR, and MS spectra.

^b Isolated yields.

^c Data for compound 4.

^d Data for compound 7.

^a All products were characterized by ¹H NMR, IR, and MS spectroscopy.

^b Isolated yields.

^c Z-isomer was obtained as the dominant product (Z-isomers > 95%, determined by ¹H NMR) before crystallization.

^d E-isomer was the only product obtained.