Stereochemistry in the Conversion of Phenyldiazomethane into Stilbenes and Spirooxetanes Caused by Tetrahalogenated 1,4-Benzoquinones. Effects of Halogen Substituents
作者:Takumi Oshima、Toshikazu Nagai
DOI:10.1246/bcsj.63.630
日期:1990.2
Reaction of phenyldiazomethane (1) with tetrafluoro-1,4-benzoquinone (2a) gave isomeric mixtures of stilbenes (3, cis/trans=4.7) and spirooxetanes (4a, cis/trans=1.1) via zwitterion intermediates. Similarly, tetrabromo-1,4-benzoquinone (2c) provided 3 and spirooxetane (4c); however, the cis/trans ratio of 3 dropped to 2.3 and 4c was solely the trans isomer. On the other hand, reaction with tetraiodo-1
苯基重氮甲烷 (1) 与四氟-1,4-苯醌 (2a) 的反应通过两性离子中间体得到二苯乙烯 (3, 顺/反 = 4.7) 和螺氧杂环丁烷 (4a, 顺/反 = 1.1) 的异构混合物。类似地,四溴-1,4-苯醌(2c)提供了3和螺氧杂环丁烷(4c);然而,顺式/反式比例 3 下降到 2.3,而 4c 仅是反式异构体。另一方面,与四碘-1,4-苯醌 (2d) 的反应不产生螺氧杂环丁烷,并进一步降低异构体比例为 3 为 1.9。