Nitronaphthalenes as Diels-Alder dienophiles

1-Nitronaphthalene, 2-nitronaphthalene and 1,3-dinitronaphthalene react wit h Danishefsky diene as normal electron demand Diels-Alder dienophiles to gi ve hydroxyphenanthrene derivatives as principal products in reasonable yiel ds. The aromatization is an expected behavior in thermal reactions involvin g nitro-substituted compounds. However, it was possible to isolate the prim ary cycloadducts when using 1,3-dinitronaphthalene, although in very low yi elds. Other less reactive dienes do not undergo cycloaddition. (C) 2000 Els evier Science Ltd. All rights reserved.