Exam 7: Cyclic Compounds and Reaction Stereochemistry

Cis-1,3-dimethylcyclohexane contains considerably smaller percentage of diaxial conformation than trans-1,2-dimethylcyclohexane. However, cis-cyclohexane-1,3-diol has a higher percentage diaxial conformation than trans-cyclohexane-1,2-diol. (For purposes of this problem, you can assume that an -OH group and a -CH₃ group have about the same size.) Explain this difference. A drawing of the diaxial chair conformation of cis-cyclohexane-1,3-diol must be part of your answer.

Consider bromine addition to alkene A below, which is the pure enantiomer. As a pure enantiomer, it is optically active, and measurement of its optical activity shows that it has (+) optical rotation.

Consider the following reaction and its stereochemistry. Select the correct statements.

Complete the following reaction by giving the structures of the missing organic products.

Draw the two chair conformations of cyclohexanol and circle the more stable conformation of the two. You only need to show the carbon-hydrogen bond at the carbon bearing the OH group (†). Bonds must be properly positioned for credit.