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Solutions to Problems 69 Boat CH₃ E 1.7 kcal mol⁻¹ Chair Chair CH₃ CH₃ Reaction coordinate to conformational interconversion 35. Both rings can flip, so there are four possible combinations, two of which are identical: H H H H These two are identical H H H Most stable: each ring is attached by an Least stable: each ring equatorial bond to the other is attached by an H axial bond to the other 36. Notice how some positions around a boat conformation of cyclohexane are axial-like ("pseudoaxial") and some are equatorial-like ("pseudoequatorial"): a a e e a = pseudoaxial e e e = pseudoequatorial a a If you draw conformations placing the methyl group in each different type of position and examine each conformation for strain, you will see the following: Methyl is pseudoequatorial CH₃ CH₃ H Best conformation Eclipsed