1,4-Addition of lithium organyls to para-quinols / structure determination of 2,6-Di-tert-butyl-4-hydroxy-4,5-diphenylcyclohex-2-en-1-one

Article abstract of DOI:10.1515/znb-1996-0314

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.