Selective esterification of the polyphenol resveratrol at the 4′-position

- The polyphenol resveratrol was selectively acylated at the 4′-position using simple reagents.
- Various 4′-esters of resveratrol are now available in moderate yields.
- Selective esterification is due primarily to the stability of the fully delocalized phenolate ion intermediate.
- Optimal conditions include use of sodium hydride or triethylamine in DMSO.

Selective esterification of the polyphenol resveratrol was performed under thermodynamic conditions using NaH and acid anhydrides to directly access 4′-esters. Standard conditions with acetyl chloride and pyridine showed poor selectivity, favoring esterification at the 3-position. The extended 4′-phenolate anion is generated in preference to the 3-phenolate under the new anhydride-sodium hydride-DMSO conditions. Acylation occurs to access the 4′-ester products with modest selectivity and yield with minimal formation of the 3-monoester, 3,5-diester, and triester products.