Abstract 2-or 3-Halonaphthoquinones are known to react with ketene dialkyl acetals and to yield 1, 3-dialkoxyanthraquinones2, 3. Various p-benzoquinones on the other hand have given only 2-alkoxy-benzofurans2. 3-Chloro-5, 7-dimethoxy-1, 4-naphthoquinone (4) and 1, 3, 6, 8-tetramethoxyanthraquinone (10), important intermediates for the synthesis of naturally occurring quinones, have now been obtained under analogous conditions using p- ...
