STUDIES OF THE SELECTIVE O-ALKYLATION AND DEALKYLATION OF FLAVONOIDS .16. DEMETHYLATION OF 2'-METHOXYACETOPHENONES WITH ANHYDROUS ALUMINUM-CHLORIDE OR BROMIDE IN ACETONITRILE
Y. Kawamura et al., STUDIES OF THE SELECTIVE O-ALKYLATION AND DEALKYLATION OF FLAVONOIDS .16. DEMETHYLATION OF 2'-METHOXYACETOPHENONES WITH ANHYDROUS ALUMINUM-CHLORIDE OR BROMIDE IN ACETONITRILE, Bulletin of the Chemical Society of Japan, 67(2), 1994, pp. 511-515
Demethylation of 2'-methoxyacetophenones with anhydrous aluminum chlor
ide in acetonitrile was studied to survey its scope and limitations. T
he mechanism which the reaction proceeds via sterically constrained in
termediates was proposed from the substituent effects. Additionally, d
ealkylation of 2'-benzyloxy-, 2'-ethoxy-, and 2'-isopropoxyacetophenon
es with two demethylating reagents, hydrochloric acid in acetic acid a
nd anhydrous aluminum bromide in acetonitrile, was studied. It was fou
nd that the reactivity was greatly affected by the steric factor betwe
en the alkoxyl group and reagent. This behavior may have wide applicat
ion in selection of protecting groups in organic synthesis.