The photoenol tautomer of 5-methyl-1, 4-naphthoquinone
作者:Erika Rommel、Jakob Wirz
DOI:10.1002/hlca.19770600106
日期:1977.1.26
Irradiation of pale yellow 5-methyl-1, 4-naphthoquinone (1, Scheme 1) yields the blue photoenol 4-hydroxy-5-methylidene-1(5H)-naphthalenone (2) which is stable at 77 K. At room temperature the enol retautomerizes to starting material, the reaction rate being strongly dependent on the hydrogen-bond-acceptor basicity of the solvent. The enol is trapped in the presence of acid by protonation at the remaining