Addition of lithium organyls to sterically hindered para-quinols leads to 1,2-or 1,4-adducts. The 1,4-addition prevails, if the 4-substituents in the quinol and the organic group in the lithium organyl are large. Four 1,4-addition products (2-cyclohex-2-en-1-ones) are synthesized and their structures investigated by NMR spectroscopy. The aryl groups at C-4 and C-5 acquire equatorial positions, the alkyl group at C-6 is bisectional. These results are confirmed by X-ray analysis of 2,6-di-tert-butyl-4-hydroxy-4,5-diphenylcyclohex-2-en-1 -one, revealing a twist boat conformation of the cyclohexene ring.
将锂有机基加入立体位阻的对奎诺醌中,可形成1,2或1,4-加成物。如果奎诺醌中的4-取代基和锂有机基中的有机基较大,则1,4-加成物占优势。合成了四种1,4-加成物(2-环己-2-烯酮),并通过NMR光谱研究了它们的结构。C-4和C-5处的芳基基团采取了赤道位置,C-6处的烷基基团是双分割的。通过对2,6-二叔丁基-4-羟基-4,5-二苯基环己-2-烯-1-酮的X射线分析,证实了这些结果,揭示了环己烯环的扭船构象。