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Question 4.64: An isomerization equilibrium between cis-decalin and trans-d......

An isomerization equilibrium between cis-decalin and trans-decalin can be established by heating the mixture to about 300 °C in the presence of a palladium catalyst. The trans isomer predominates. Why is the trans isomer more stable than the cis isomer?

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The ring junction in cis-decalin is equatorial axial, so there are always unfavorable 1,3-diaxial interactions; but, in trans-decalin, the ring junction is diequatorial, and there are fewer unfavorable steric interactions.

لقطة الشاشة 2023-08-06 215221

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