FLAVONOIDS, 39. THE REACTION OF 3-MESYLOXYFLAVANONES WITH O- AND S-NUCLEOPHILES, SYNTHESIS OF 3-THIOCYANATO- AND 3-ACETYLTHIO-FLAVANONES

Article abstract of DOI:10.1016/S0040-4020(01)91491-7

The action of either cyanate or acetate ions on trans-3-mesyloxyflavanones 1 led to the formation of flavones 2 and aurones while the reaction with the respective S-nucleophiles (thiocyanate and thioacetate ions) resulted in cis- and trans-3-thiocyanato- and 3-acetylthioflavanones (6 and 11).The participation of the concurrent nucleophilic substitution, β-elimination and elimination with ring-contraction is dependent on the "hard-soft" character of the nucleophile and the increase of the "soft" character favours the displacement.