2-Methyl-2-phenyl-l,3-dioxanes

The preferred conformations of both 1-methyl-l-phenylcyclohexane and 2-methyl-2-phenyl-l,3-dioxane have the phenyl group in the axial orientation even though the conformational flee energy of the phenyl group (2.9 kcal) is greater than that for a methyl group (1.8 kcal). Explain. 

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