ent Name: Secti 9-15 in Class Notes ctice Problems plete the following problems. You should utilize the ModelAR application as needed to help view ctures. 1. 2. Convert each of the following Newman Projections to a bond-line formula. Use wedge and dash bonds to illustrate groups that are out-of-plane. H Br CH3 CH3 H3C Hilma Br H OH H 10121 Draw a Newman projection for each of the following, looking down the bond indicated with an arrow. Pay close attention to the 3-dimensional structure. ШIOH CH3 Linda soloyo betu CI, H CH3 HO CH3 H CH3 CH₂CH3 CH3

Problems: 1. Use MO Theory to determine which (if either) of the cyclopentadiene cation or cyclopentadiene anion is aromatic. a. Determine the number of potential pi electrons in each molecule. b. Determine the constructive vs destructive interactions and the energies for the MOs of a 5 carbon pi system. The nodes are provided below to get you started. c. Fill in the pi electrons for the cation and anion into the energy diagram. Cation (continued on the next page) Anion d. Relate the MO diagrams to their aromaticity (or lack thereof). What orbital hybridization would the empty orbital or lone pair adopt?

Answer the ones listed below

Learning Target 5 Criteria for satisfactory score All molecular drawings must be valid Lewis structures (octet rule, formal charge, valence, geometry). Definitions and explanations must be complete and logical. Tasks A-value Substituent (kJ/mol) CI 2.0 ОН 4.2 CH3 7.6 Et 8.0 i-Pr 9.2 t-Bu 22.8 Figure 3: Substituted cyclohexane 1. Draw a chair conformation of the molecule in Figure 3 and it's ring flip conformer 2. Select the lower energy chair conformation and briefly explain your choice. Estimated values of diaxial interactions for various substituents (A-values) are listed in the table. 3. Boat conformation of cyclohexane does not experience ring strain. Nevertheless it is significantly less stable than the chair conformation. There are two types of strain that cause it. One is flagpole interactions. What is the second reason for higher energy of the boat conformation of cyclohexane? Drawing must be used as part of your answer.