SYNTHESIS AND UNAMBIGUOUS ASSIGNMENT OF STRUCTURE TO PYRANO[4,3-<i>c</i>]PYRAZOL-4(1<i>H</i>)-ONES AND -4(2<i>H</i>)-ONES
作者:Albert Cantos、Pere De March、Marcial Moreno-Mañas、Anna Pla、Francisco Sanchez-Ferrando、Albert Virgili
DOI:10.1246/cl.1986.295
日期:1986.3.5
A clean synthesis of pyranopyrazolones is described. The reactions of 4-chloro-3-(1-chlorovinyl)-6-methyl-2-pyrone with arylhydrazines give pyrano[4,3-c]pyrazol-4(2H)-ones as the only identified products. However, the isomeric pyrano [4,3-c]pyrazol-4(1H)-ones have been isolated when alkylhydrazines were used. Unambiguous assignment of structure could be achieved by homonuclear 1H1H} NOE determinations
描述了吡喃并吡唑啉酮的清洁合成。4-氯-3-(1-氯乙烯基)-6-甲基-2-吡喃酮与芳基肼的反应产生吡喃并[4,3-c]吡唑-4(2H)-酮作为唯一确定的产物。然而,当使用烷基肼时,已分离出异构吡喃并 [4,3-c] 吡唑-4(1H)-酮。通过同核 1H1H} NOE 测定可以实现结构的明确分配。