Synthesis and Autoxidation of 2,3,4-Trimethylnaphthalen-1-ol and Related Naphthalen-1-ols

Abstract

The oxidation of 2-methylnaphthalene, 1,2-dimethylnaphthalene, 2,3-dimethylnaphthalene, and 1,2,3-trimethylnaphthalene by lead tetraacetate in dichloroacetic acid and chloroform gave fair to low yields of the dichloroacetyl derivatives of 2-methylnaphthalen-1-ol, 3,4-dimethylnaphthalen-1-ol, 2,3-dimethylnaphthalen-1-ol, and 2,3,4-trimethylnaphthalen-1-ol respectively. In the case of 1,3-dimethylnaphthalene, dichloroacetoxylation was not observed, and the only isolated product was the binaphthyl (10). 2,3,4-Trimethylnaphthalen-1-ol, obtained on hydrolysis of the dichloroacetyl derivative, was very sensitive to oxygen even in the solid state, and when shaken in chloroform in an oxygen atmosphere gave 4-hydroperoxy-2,3,4-trimethylnaphthalen-l-(4H)-one (14). A study of the autoxidation of the naphthalen-1-ols (7), (19) and (20) led to the conclusion that the oxygen-sensitivity of (11) resulted from a 4,5 peri interaction.