Chemistry Problem Set: Lewis Structures, Resonance, Functional Groups, and Reactions, Exams of Organic Chemistry

Download Chemistry Problem Set: Lewis Structures, Resonance, Functional Groups, and Reactions and more Exams Organic Chemistry in PDF only on Docsity! 1. a) Draw the completed Lewis structure (show each atom, including carbons and hydrogens, electron pairs, and charges) of compound A below. [4 pts] b) Draw the conjugate base of compound A (you can use skeletal structure). Show all electron pairs and charges. [4 pts] c) Draw the relevant resonance structures for the conjugate base of compound A (you can use skeletal structures). Show all electron pairs, charges, and arrows. [4 pts each] d) Circle the most stable resonance structure (major contributor) [2 pts] e) Predict the direction of the equilibrium. [3 pts each] 2. a) For the structure below, provide a chemical formula [2pts], name [3pts], and propose a structure of constitutional isomer and stereoisomer [4pts each]. b) For the following structure, determine functional groups [1pt each]: c) How many carbon atoms are sp hybridized? [2 pts] d) How many carbon atoms are sp2 hybridized? [2 pts] e) How many heteroatoms (all except carbon) are sp3 hybridized? [2 pts] Functional group a b c d e f g h 5. a) Show the orbital overlap for the following molecule, indicate bonds (𝜎 or 𝜋) and lone pairs [6 pts]. b) Draw the Newman projection of the most stable (lowest energy) conformer for the following molecule when looking down the indicated arrow [5 pts]. c) Draw the most stable (lowest energy) chair conformation for cis-4-ethylcyclohexanol [5 pts]: 1. a) Draw the completed Lewis structure (show each atom, including carbons and hydrogens, electron pairs, and charges) of compound A below. [4 pts] b) Draw the conjugate base of compound A (you can use skeletal structure). Show all electron pairs and charges. [4 pts] c) Draw the relevant resonance structures for the conjugate base of compound A (you can use skeletal structures). Show all electron pairs, charges, and arrows. [4 pts each] d) Circle the most stable resonance structure (major contributor) [2 pts] e) Predict the direction of the equilibrium. [3 pts each] 2. a) For the structure below, provide a chemical formula [2pts], name [3pts], and propose a structure of constitutional isomer and stereoisomer [4pts each]. b) For the following structure, determine functional groups [1pt each]: c) How many carbon atoms are sp hybridized? [2 pts] d) How many carbon atoms are sp2 hybridized? [2 pts] e) How many heteroatoms (all except carbon) are sp3 hybridized? [2 pts] Functional group a b c d e f g h 5. a) Show the orbital overlap for the following molecule, indicate bonds (𝜎 or 𝜋) and lone pairs [6 pts]. b) Draw the Newman projection of the most stable (lowest energy) conformer for the following molecule when looking down the indicated arrow [5 pts]. c) Draw the most stable (lowest energy) chair conformation for trans-3-ethylcyclohexanol [5 pts]: 1. a) Determine the configuration of the double bond (E/Z) or the chiral center (R/S) in the following molecules [2 pts each]: b) Specific rotation of pure (S)-1-iodo-2-methylbutane is +5.70º. Draw (S)-1-iodo-2-methylbutane [3 pts]: The mixture of (S)-1-iodo-2-methylbutane and (R)-1- iodo-2-methylbutane has a specific rotation of +2.85º. What is the enantiomeric excess of this mixture [2pts]: What is the percentage of (S)-1-iodo-2-methylbutane in this mixture [2 pts]: c) Name compound A shown below [3 pts]. Draw the enantiomer and diastereomer of the compound A [3 pts each]: the enantiomer of the compound A the diastereomer of the compound A 2. Determine the mechanism for each reaction: SN1, SN2, E1, E2, R (rearrangement), AB (acid-base), or Ad (addition) [3 pts each]: 5. a) Provide a detailed stepwise mechanism for the following reaction [9 pts]: b) Draw a reaction-energy diagram for the reaction in part a). Clearly label the starting material (SM), transition state(s) (TS), intermediate(s) (I), product (P), and the rate-determining step (RDS). [8 pts] 1. a) Determine the configuration of the double bond (E/Z) or the chiral center (R/S) in the following molecules [2 pts each]: b) Specific rotation of pure (R)-1-iodo-2-methylbutane is −5.70º. Draw (R)-1-iodo-2-methylbutane [3 pts]: The mixture of (R)-1-iodo-2-methylbutane and (S)-1- iodo-2-methylbutane has a specific rotation of −2.85º. What is the enantiomeric excess of this mixture [2pts]: What is the percentage of (R)-1-iodo-2-methylbutane in this mixture [2 pts]: c) Name compound A shown below [3 pts]. Draw the enantiomer and diastereomer of the compound A [3 pts each]: the enantiomer of the compound A the diastereomer of the compound A 2. Determine the mechanism for each reaction: SN1, SN2, E1, E2, R (rearrangement), AB (acid-base), or Ad (addition) [3 pts each]: 5. a) Provide a detailed stepwise mechanism for the following reaction [9 pts]: b) Draw a reaction-energy diagram for the reaction in part a). Clearly label the starting material (SM), transition state(s) (TS), intermediate(s) (I), product (P), and the rate-determining step (RDS). [8 pts] 1. a) For each pair, circle the most stable intermediate. [2 pts each] b) Estimate the pKa for each proton indicated below. [2 pts each] c) Circle the major product for each reaction below. [3 pts each] d) Circle the starting alkene that produced the mixture of aldehydes shown below during the ozonolysis reaction. [3 pts] 2. a) Draw the major product for each reaction below. [4 pts each] b) Draw the polymer structure derived from the alkene shown below during free radical polymerization. Show at least three units. [4 pts.] c) Propose the Williamson synthesis of the following ether starting from two alcohols. [2 pts. each structure] 2. a) Draw the major product for each reaction below. [4 pts each] b) Draw the polymer structure derived from the alkene shown below during free radical polymerization. Show at least three units. [4 pts.] c) Propose the Williamson synthesis of the following ether starting from two alcohols. [2 pts. each structure] 3. a) Draw the product for each reaction. Show stereochemistry (wedges and dashes) [4 pts each]. b) Draw the product for each reaction below. [4 pts each].