The reactions of 3-nitro-2-phenyl-2H-chromenes with 2-arylmethylidene-5-oxopyrazolidin-2-ium-1-ides proceeded diastereoselectively to afford the corresponding tetrahydrochromeno[4,3-c]pyrazolo[1,2-a]pyrazol-11-ones in good yields as a result of the 1,3-dipolar cycloaddition reaction of stabilised N,N′-cyclic azomethine imines at the Δ³-bond of the chromene system.

中文翻译：

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稳定的N，N'-环偶氮甲亚胺与3-硝基-2-苯基-2 H-色烯的高度立体选择性[3 + 2] -环加成反应：合成四氢色素[4,3- c ]吡唑并[1,2-一个]吡唑-11-那些

3-硝基-2-苯基-2 H-色烯与2-芳基亚甲基-5-氧吡唑并丁-2-鎓-1的反应非对映选择性地进行，得到相应的四氢色素[4,3- c ]吡唑并[1,2]。 -一个]吡唑11酮以良好的收率作为稳定1,3-偶极环加成反应的结果ñ，ñ在Δ' -环甲亚胺亚胺³色烯系统的-键。