抄録
Diels-Alder reaction of 5-nitro-1, 4-naphthoquinone (1) and unsymmetrical butadienes was carried out. Reaction of 1 and 2-methyl-1, 3-butadiene gave 1, 4, 4a, 9a-tetrahydro-2-methyl-5-nitro-anthraquinone (2) and its 3-methyl analogue (3) at the ratio of 9.2 : 1. Reaction of 1 and 1, 3-pentadiene gave 1, 4, 4a, 9a-tetrahydro-1-methyl-8-nitroanthraquinone (8) and its 5-nitro analogue (9) at the ratio of 10 : 7. Their structures have been determined by aromatization to methyl-nitroanthraquinones.
