Aromatization of Arene 1,2-Oxides. Comparison of the Aromatization Pathways of 1-Carboxy-, 1-Carbomethoxy-, 1-Formyl-, 1-(Hydroxymethyl)-, and 1-(2-Hydroxy-2-propyl)benzene Oxide

Article abstract of DOI:10.1021/ja00394a029

The mechanisms for aromatization of the title compounds in 1:1 tetrahydrofuran/water at various pHs have been investigated through product studies and studies with the deuterium-labeled arene oxides.Arene oxide 8 isomerizes to methyl salicylate; the extent of carbomethoxy migration during product formation is 70percent at pH 0.1 and 83percent at pH 7.Arene oxide 9 affords salicylic acid (40percent at pH 1, 20percent at pH 7) and phenol (60percent at pH 1; 80percent at pH 7); salicylic acid is formed without migration of the carboxyl group.Aromatization of 10 (pH 0.1-10) gives phenol (88-94percent) and salicylaldehyde (6-12percent) without migration of the formyl group.Aromatization of 11 (pH 1.1-10) geves phenol (8-17percent) and o-hydroxybenzyl alcohol (83-92percent) without migration of the side chain.Phenol (40-45percent) and o-(2-hydroxy-2-propyl)phenol (55-60percent) are formed from 12 during aromatization at pH 1.1-10.