Figure Number: 11-00CO Title: Elimination Reaction Caption: Electrostatic potential maps and structures of reactants and products of the elimination reaction undergone by methoxide and 3-chloropentane. Notes: Elimination reactions occur when nucleophiles act as bases rather than nucleophiles. The nucleophile removes a proton on the carbon adjacent to the carbon containing the leaving group. The sigma bond between this adjacent carbon and the hydrogen becomes a pi bond between the adjacent carbon and the carbon bearing the leaving group, and the leaving group leaves. These steps, done in different orders in different circumstances, yield alkene products.

Figure Number: 11-00-04.1UN Title: E2 Reactivities Caption: Relative reactivities of alkyl halides in E2 reactions. Notes: Alkyl halides with better leaving groups react faster by E2 than do alkyl halides with poor (unstable) leaving groups.

Figure Number: 11-01 Title: Figure 11.1 Caption: Reaction coordinate diagram for the E2 reaction of 2-bromobutane and methoxide ion. Notes: Since the transition state is somewhat product-like, formation of the more stable internal alkene product involves a more stable transition state, less activation energy, and a faster relative rate.

Figure Number: 11-01-05.1UN Title: Products of E2 Reactions Caption: Products of the reactions of hydroxide ion with 4-chloro-5-methyl-1-hexene and 2-bromo-3-methyl-1-phenylbutane. Notes: E2 reactions usually yield predominantly the most stable alkene products, which in this case is the conjugated alkene products.

Figure Number: 11-01-07T01 Title: Table 11.1 Effect of steric properties on distribution of products in an E2 reaction Caption: Notes:

Figure Number: 11-01-09T02 Title: Table 11.2 More substituted product/ Less substituted product Caption: Products obtained from the E2 reaction of methoxide and 2-halohexanes. Notes: The reaction with fluoride leaving group yields the less stable terminal alkene product predominantly. With fluoride as the leaving group, the transition state resembles the carbanion obtained by removing hydrogen from a carbon adjacent to the carbon bearing the leaving group more than it (the transition state) resembles the product alkene. Since a primary (terminal) carbanion is more stable than a secondary (internal) carbanion, this reaction yields mostly terminal olefin. The hydrogen is abstracted from the terminal carbon in preference to the internal carbon.

Figure Number: 11-01-25.1UN Title: Hyperconjugation Caption: Orbital picture of a carbocation stabilized by hyperconjugation. Notes: Hyperconjugation makes a hydrogen attached to a carbon adjacent to a carbocation more acidic.

Figure Number: 11-02 Title: Figure 11.2 Caption: Reaction coordinate diagram for the E1 reaction of 2-chloro-2-methylbutane with base. Notes: The major product is the more stable alkene, because both products come from a common intermediate and the relative stabilities of the transition states leading to products from the common intermediate determine which product forms faster, even though these transition states occur after the rate-determining step. The second transition state in the reaction path has a small amount of product character, so the transition state leading to the more stable product is slightly more stable.

Figure Number: 11-02-01UN Title: Alkyl Effect on E1 Reactivities Caption: Relative reactivities of alkyl halides in an E1 reaction. Notes: Relative reactivities of alkyl halides in E1 reactions parallels the stabilities of the corresponding alkyl cations.

Figure Number: 11-02-01.1UN Title: Leaving Group Effect on E1 Reactivities Caption: Relative reactivities of alkyl halides in an E1 reaction. Notes: Relative reactivities parallel leaving-group (halide) stability.

Figure Number: 11-03 Title: Figure 11.3 Caption: Reaction coordinate diagram for the E2 reaction of 2-bromopentane with ethoxide ion. Notes: The more stable E alkene has the more stable transition state, so it is formed more rapidly than the Z alkene.

Figure Number: 11-03-00UN Title: (E)- and (Z)-2-pentene Caption: Electrostatic potential maps and structures of (E)-2-pentene and (Z)-2-pentene. Notes: (Z)-2-Pentene is less stable because of steric repulsions between hydrogens attached to the methyl and ethyl groups situated on the same side of the double bond, as can be seen from the potential maps.

Figure Number: 11-03-30UN Title: Deuterium Kinetic Isotope Effect Caption: Definition of deuterium kinetic isotope effect. Notes: Deuterium kinetic isotope effects greater than 1.0 indicate that the bond attaching H or D to the molecule under study is being broken in the rate-determining step.

Figure Number: Title: Table 11.3  Summary of the Reactivity of Alkyl Halides in Elimination Reactions Caption: Notes:

Figure Number: Title: Table 11.4 Stereochemistry of Substitution and Elimination Reactions Caption: Notes:

Figure Number: Title: Table 11.5  Relative Reactivities of Alkyl Halides Caption: Notes:

Figure Number: Title: Table 11.6  Summary of the Products Expected in Substitution and Elimination Reactions Caption: Notes:

Figure Number: 11-01-07T01 Title: Table 11.1 Effect of steric properties on distribution of products in an E2 reaction Caption: Notes:

Figure Number: 11-01-09T02 Title: Table 11.2 More substituted product/ Less substituted product Caption: Products obtained from the E2 reaction of methoxide and 2-halohexanes. Notes: The reaction with fluoride leaving group yields the less stable terminal alkene product predominantly. With fluoride as the leaving group, the transition state resembles the carbanion obtained by removing hydrogen from a carbon adjacent to the carbon bearing the leaving group more than it (the transition state) resembles the product alkene. Since a primary (terminal) carbanion is more stable than a secondary (internal) carbanion, this reaction yields mostly terminal olefin. The hydrogen is abstracted from the terminal carbon in preference to the internal carbon.