Problem Set 4 C2211 01 w18 PDF

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The 4th problem set given for Dr. Hilinski's CHM 2211 course....

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CHM 2211 – Problem Set 4

1. Provide an efficient multistep synthesis for each of the conversions, shown to the right (a-f) of ethylbenzene into the given target molecule. Each C in each target molecule must come from ethylbenzene. For each functional group transformation, give all necessary reagents, solvents, and catalysts; give a structural formula of the organic reactant and the major organic product(s). Show stereochemistry appropriately when necessary. If a mixture of products (for example an ortho-para mixture or a mixture of diastereomers) must be present after a step, assume that you can separate the mixture and take the one needed product forward through the next step.

2. Provide an efficient multistep synthesis for the conversion of the given starting material into the target molecule shown to the right. You must begin with the given starting organic compound. All Cs that end up in the target compound must come from the given starting organic compound. For each functional group transformation, give all necessary reagents, solvents, and catalysts; give a structural formula for each organic reactant and the major organic product(s). Show stereochemistry appropriately when necessary. If a mixture of products (for example a mixture of stereoisomers) must be present after a step, assume that you can separate the mixture and take the one needed product forward through the next step. 3. Consider the possibilities of attack of an electrophile E+ on anisole to give ortho, meta, and para substitution. Carefully showing all the valence electrons and all formal charges, give all relevant resonance structures for the cyclohexadienyl cation intermediates and provide a clear, concise, but detailed, explanation for which one (or ones) [ortho, meta, para] is(are) the major product(products). 4. Using arrows to show the flow of electrons, give a stepwise mechanism for the reaction shown below. You do not need to give more than one Lewis structure (resonance structure) for any reactive intermediates.

CHM 2211 – Problem Set 4

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5. Using arrows to show the flow of electrons, give the mechanism for the formation of the electrophile in each of the following reactions. Show only how the electrophile is formed and NOT the entire mechanism for the reaction.

6. Each of the following is involved in one or more of the types of organic chemical reactions that we have covered.

For each part (a, b, and c), select an organic reaction in which the given entity is involved and give a chemical equation for your selected organic reaction that includes the following in each of your answers: (i) structural formula(s) for the organic reactant(s); (ii) a structural formula for the major organic product; and (iii) the experimental conditions (Give structural formulas for organic compounds. Give a chemical formula for inorganic reactants or catalysts . If heat and/or light is needed, be sure to indicate it appropriately.) As we do for most organic reaction equations, the chemical equations that you give do not need to be balanced. _

EXAMPLE:

For the involvement of

.. .

in an organic chemical reaction, here is an acceptable answer. Na, NH3 CH3OH

7. For each of the following, supply a structural formula for the major organic product(s) when the product(s) is(are) not given; if no reaction occurs, write N.R. If the major product is a mixture (for example, enantiomers, stereoisomers, or an ortho-para mixture), give a structural formula for each of the isomers in the mixture. Provide the following when a product is given. If an organic reactant is missing, supply a structural formula; if an inorganic reactant (reagent) or catalyst is missing, simply give a formula. If heat and/or light is needed, be sure to indicate it appropriately if these conditions are missing. NOTE: You cannot use ClCO2H or HCOCl (or their analogous anhydrides) in a Friedel-Crafts reaction. Also NOTE that you cannot use alkenyl, alkynyl, or aryl halides in a Friedel-Crafts reaction. Give the best possible answers. Be sure to show stereoisomers properly when necessary.

CHM 2211 – Problem Set 4 [ANSWERS begin on p. 3—Other answers may be acceptable.]

1a)

1b)

1c)

1d)

1e)

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CHM 2211 – Problem Set 4 Page 4 [ANSWERS begin on p. 3—Other answers may be acceptable.]

1f)

2)

CHM 2211 – Problem Set 4

3)

4)

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CHM 2211 – Problem Set 4

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5a)

5b)

6a)

iii i → ii

6c)

iii i → ii

6b)

iii i → ii

CHM 2211 – Problem Set 4

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1a)

1b)

1c)

1d)...