Stereochemical Considerations in Planning Syntheses

Chapter 2 focuses on conformational analysis as a tool for assessing the relative reactivity and stereochemistry of cyclic compounds. 

Problems 1-3 emphasize the three dimensional representation of various cyclic molecules and evaluation of their energies by the A, G, and U parameters. In Problems 4-6, we apply conformational analysis to predict the reactivity of carbocyclic systems toward various reagents and to gather information regarding the preferred stereochemical course of the corresponding reactions. Further examples of applications of conformational analysis in organic synthesis are incorporated in Problems 7-9. 

Draw the chair or the half-chair conformations (where applicable) for each of the molecules shown below and determine the corresponding ED and AED values. Use the A, G, and U values of Table 2.3 and assume 0.7 kcal/mol for Me/H A1 2 strain. 

Draw the most stable conformation for each of the compounds shown below. You do not need to compute the ED and AEd values. 

For each molecule shown below, calculate the percentage (%) of the more stable conformation at the temperature indicated. 

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