Reactions of tetrahalogeno-o-benzoquinones Part VI: reactions of tetrachloro-o-benzoquinone with methyl naphthols-formation of naphthoquinone methides

Abstract

The oxidation of a few methyl naphthols with tetrachloro-o-benzoquinone (1) has been described. Reaction of 1-methyl-2-naphthol (4) with the quinone (1) was found to give the spirodimer, 1,1',2,2'-tetrahydro-3H-benzo (f) chromen-3-spiro-1'-naphthalene-2'-one (6) and a yellow solid which has been assigned the structure of 5,6,7,8-tetrachloro-1,4-benzodioxan-2-spiro-1'-naphthalen-2'-one (7) on the basis of chemical and spectral data. Among the other naphthols studied, 4-methyl-2-t-butyl-1-naphthol afforded 5,6,7,8-tetrachloro-1,4-benzodioxan-2-spiro-1'-naphthalen-3'-t-butyl-4'-one (22) while 2-methyl-1-naphthol and 4-methyl-1-naphthol gave 2-methyl-4,4-(tetrachloro-o-phenylenedioxy) naphthalen-1(4H)-one(15) and 4-methyl-2,2-(tetrachloro-o-phenylenedioxy) naphthelen-1(2H)-one (19) respectively. The present study has shown that oxidation of suitably substituted naphthols with the quinone (1) gives rise to naphthoquinone methides.