Intramolecular cyclization reactions of 5-halo-and 5-nitro-substituted furanylamides were examined. The 2-alkoxy-5-bromofuran derivative 2 produced the rearranged dihydroquinone 6 (36%), a product from the rearrangement of the intermediate oxabicycle 3. The 5-halo substituted furoyl amide 18 was converted to the polyfunctional oxabicycle 20 in 82% yield and at a much faster rate than the unsubstituted furanyl system 17. The 5-nitro- ...