1) (20 pts) Complete the following reaction scheme with appropriate reagents and products in the
intermediate steps. Show correct stereochemistry when applicable.
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2) (9 pts) Provide IUPAC names for the following compounds. Include stereochemistry such as cis,
trans, E, Z, R and S when appropriate.
__ (R)-7-bromo-1-isopropylcyclohept-1-ene___
____ (Z)-3,7-dimethyloct-3-ene_____
____ 5-chloro-2-nitrobenzaldehyde___
3)
Draw structures for the following. Use solid wedges and hashes to show stereochemistry when
appropriate.
a) (3 pts) Draw the structure of an optically active isomer of 1,2-dichlorocyclopentane.
b) (3 pts) Draw the structure of a meso isomer of 2,3-dibromobutane
c) (3 pts) Draw the Newman projection for a most stable conformer 1,2-dichloroethane
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d) (3 pts) Draw a least stable chair conformation for trans-1-chloro-3-isopropylcyclohexane.
[Clearly indicate axial and equatorial positions]
e) (3 pts) The steric strain for this conformational structure is ____ (2
[some useful data are provided on the front page]
 4.6 = 9.2 )_____ kJ/mol.
4) (4 pts) Show two resonance structures for the following ion. To save you time, two more skeletal
structures are given below. Make sure to complete the structures with formal charges on the needed
atom to show the resonance structures, and arrow-pushing of electrons when you go from one structure
to the other.
(Remember to add other bonds that did not change from 1st structure)
5) (3 pts) How many 1H-NMR signals are expected for the following compounds. [In other words, how
many non-equivalent groups (or set) of protons are in these molecules?]
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6) Consider the following sequence of reactions steps.
a) (6 pts) Show one initiation, one propagation and one termination step for the reaction involved
in Step-1 to get the indicated product. Show correct arrow-pushing of electrons.
Initiation:
Propagation:
Termination:
b) (2 pts) What is the possible mechanism for Step-2? Circle one.
SN1
SN2
E1
E2
E1CB
c) (5 pts) Show a detailed mechanism for Step-2. Show all the steps, intermediates, formal charges
etc, for full credit.
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7) (6 pts) Identify the structure of a compound with molecular formula C8H18O and has the following
spectral features:
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H-NMR:
1.13 ppm (6 H, doublet)
1.25 (9H, singlet)
3.65 (1H, septet)
3.79 ppm (2H, singlet)
8) (8 pts) Compound A, a hydrocarbon with M+ = 96 in its mass spectrum, has the 13C spectral data
given below. On reaction with KMnO4 in acid medium, A converted into B and carbon dioxide.
Based on the spectral data provided below, propose a possible structure for A and B.
Compound-A:
Broad-Band Decoupled 13C-NMR: 26.8, 28.7, 35.7, 106.9, 149.7 ppm
DEPT-90: no peaks
DEPT-135: no positive peaks; negative peaks at 26.8, 28.7, 35.7, 106.9 ppm
Compound-B:
Broad-Band Decoupled 13C-NMR: 26.1, 26.5, 29.9, 175.3 ppm
DEPT-90: no peaks
DEPT-135: no positive peaks; negative peaks at 26.1, 26.5, 29.9 ppm
Structure of A
Structure of B
9) (3pts) Among the following molecules/ions, circle ALL that are aromatic. [Check all that apply]
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10) (4 pts) Classify the following sets of protons as unrelated, homotopic, enantiotopic or diastereotopic.
Diastereotopic
Enantiotopic
11) (7 pts) Are the following TRUE for E1, E2, or E1CB? There could be more than one correct
answer for each statement. But selecting incorrect answer may result in negative points.
Reaction goes through a carbanion
E1
E2
E1CB
Faster rate if anti-periplanar geometry is possible
E1
E2
E1CB
Leaving groups such as OCH3, OH and NH2 can be eliminated
E1
E2
E1CB
Relatively mild (or weak) nucleophile is needed
E1
E2
E1CB
sp2 hybridized intermediate is involved after leaving group leaves
E1
E2
E1CB
The slow step involves only one reactant molecule
E1
E2
E1CB
12) (3 pts) Consider the reaction of H-Br with the following molecule. Draw the structure of the
product if the attack of the Br selectively occurs from the Re-face. [Show correct stereochemistry]
(3 pts) Whether the product formed in the above reaction would be optically active or inactive?
Active, because _______________________________________________
OR
Inactive, because ______Meso
product__________
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13) (8 pts) Propose a detailed synthesis for any ONE of the following transformations. Be sure to
include the products of each step. Retrosynthetic analyses are not required, but may be helpful
to you. Only syntheses presented in the forward direction will be graded. Strike out the one
that you don’t want to be graded.
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