Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5271119 | Tetrahedron Letters | 2014 | 4 Pages |
â¢The polyphenol resveratrol was selectively acylated at the 4â²-position using simple reagents.â¢Various 4â²-esters of resveratrol are now available in moderate yields.â¢Selective esterification is due primarily to the stability of the fully delocalized phenolate ion intermediate.â¢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 4â²-esters. Standard conditions with acetyl chloride and pyridine showed poor selectivity, favoring esterification at the 3-position. The extended 4â²-phenolate anion is generated in preference to the 3-phenolate under the new anhydride-sodium hydride-DMSO conditions. Acylation occurs to access the 4â²-ester products with modest selectivity and yield with minimal formation of the 3-monoester, 3,5-diester, and triester products.
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