strong polar influences, 4,4,5-substituted cyclopentenones predominate over their 4,5,5-isomers when trisubstituted alkenes are employed in the Khand reaction. Double bonds shifts prior to annellation are a feature of two of the examples studied. Efficient use of these relatively unreactive alkenes is made possible by employing an acetylene/carbon monoxide atmosphere to allow recycling of the cobalt
提出的结果表明,在Khand反应中使用三取代的烯烃时,在没有强极性影响的情况下,4,4,5-取代的
环戊烯酮比其4,5,5-异构体占优势。匿名化之前的双键移位是所研究的两个示例的特征。通过使用
乙炔/
一氧化碳气氛以允许
羰基钴片段的再循环,可以有效地使用这些相对不活泼的烯烃。