New Route to Dimethylnaphthalenes Involving Cyclization of Ylidenemalonodinitriles and Ethyl Ylidenecyanoacetates; Part 21. Synthesis of 1,7-, 2,6-, and 2,7-Dimethylnaphthalene
New Route to Dimethylnaphthalenes Involving Cyclization of Ylidenemalonodinitriles and Ethyl Ylidenecyanoacetates; Part 2<sup>1</sup>. Synthesis of 1,7-, 2,6-, and 2,7-Dimethylnaphthalene