Atropisomerism of the 1,3-cyclohexadiene Derivatives Induced by Steric Congestion

作者：Nakayama Juzo^*; Iguchi Kazuki; Fujihara Takashi

来源：Phosphorus, Sulfur, and Silicon and the Related Elements, 2010, 185(5-6): 1131-1141.

DOI：10.1080/10426501003773472

• Atropisomerism
• Diels-Alder reaction
• 3
• 4-di-tert-butyl-2
• 5-dimethylthiophene 1-oxide
• steric congestion
• X-ray diffraction analysis

3,4-Di-tert-butyl-2,5-dimethylthiophene 1-oxide (2) reacted with maleic anhydride to give the Diels-Alder adduct quantitatively. Oxidation of the sulfinyl group of the adduct and the thermal extrusion of sulfur dioxide from the resulting sulfone furnished 4,5-di-tert-butyl-3,6-dimethyl-3,5-cyclohexadiene-1,2-dicarboxylic acid anhydride (8) quantitatively. 8 showed atropisomerism that originates from the inhibited ring inversion of the cyclohexadiene ring by steric congestion. Mixtures of atropisomers were also obtained from the adducts of 2 and 1,4-benzoquinones.

• 出版日期2010