imagine a cyclohexane chair structure with 3 methyl groups attached to (1 methyl each) carbon 1, carbon 2, carbon 3.
structure A has it attached at carbon 1 as axial, at carbon 2 as equatorial , carbon 3 as axial
structure B has it attached at carbon 1 as axial, carbon 2 as axial, and carbon 3 as equatorial
which is more stable?
structure A has it attached at carbon 1 as axial, at carbon 2 as equatorial , carbon 3 as axial
structure B has it attached at carbon 1 as axial, carbon 2 as axial, and carbon 3 as equatorial
which is more stable?
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Both A and B have 2 axial and 1 equitorial methyl groups. The 1, 3 CH3 / CH3 diaxial interactions in A are worse than the 2 CH3 /H interactions in B. B is lower energy.
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B because A has a 1,3-diaxial interaction.