Fall 06 Organic I Final Exam 200pts (graded as 300pts) Name If you ...
Transcript of Fall 06 Organic I Final Exam 200pts (graded as 300pts) Name If you ...
Fall 06 Organic I Final Exam 200pts (graded as 300pts) Name If you do not want your graded exam placed in the box outside my office, then please tick here 1) (6pts total) Give one definition of ORGANIC CHEMISTRY. b) What makes each element unique? c) What is the requirement for a covalent bond to be considered polar? 2) Briefly explain what is meant by the following terms:(16pts total) Free radical Chiral Molecule Racemic Mixture Rate Determining Step Syn Addition Mechanism Kinetics Terminal alkyne
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3) Name the classes of compound that the following molecules belong to (E.g. alkane,
amide, etc). (18pts)
O
RR
O
O-HRR S-H
R OR
O
R OO
H
O
RO
OR
RO
R
RO
HPO
O OHOH
R
4) Draw Lewis structures (sticks for bonds, and dots for lone pairs) for the below three
molecules. (9pts) (a)
(b)
(c)NH2
CH2Cl2
CH2CHF
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5) For the below molecule: (8pts)
OH
H
NH2
BrFN
How many sp hybridized carbons? How many sp2 hybridized carbons? How many Hydrogens? How many chiral centers? 6) Classify each of the following reactions as an Elimination, Addition or Substitution. (5pts)
(c)
(d)
(b)
(a)
(e)
CH3H3C
OH
H3CH
Cl
Cl
HCH3CH3H3C
PhH
Br
Br
HPh
H Ph
HPh
H3C
CH3F
H
H3C CH2OHOCH3
H
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7) Explain why in this electrophilic addition reaction, none of product A is generated, and product B is formed exclusively. Your answer should include curly arrows (and also someone’s name that starts with M) to receive maximum points! (9pts)
F
H
H
CH3
H-FH-F
Product BProduct A
X CH3HH
H
F
CH3
8) Draw an energy level diagram for a typical exothermic E1 process. Make sure to label (a) the axes (b) the reactants and products (c) any transitions states (d) ΔHo for the overall reaction (e) the rate determining step (9pts)
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9) By considering the hybridization of the central atom, predict the shape and bond angles of H3O+. (5pts) 10) Name the following molecules in IUPAC form. (15pts)
(c)
(d)
(b)
(a)
(e)
CH3
CH2CH3Br
I
OH
Cl
CH2CH2CH2CH2CH3H
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11) Assign R or S to each chiral center in these molecules. (12pts)
Cl
HO CH3F
CO2HHClHH
CF3
Cl
H
CH2
F
F
(c)
(d)
(b)
(a)
O
O
NHCH3
CH3H
HH
12) What is the name of the type of Projection used in part (d)? (2pts) (b) Who invented the priority convention for assigning R and S to chiral centers? (2pts)
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13) Explain mechanistically the observation that when Br2 is added to cyclohexene, the Bromine atoms end up anti to one another. (10pts)
Br-Br BrBr
anti dibromide 14) Draw the lowest energy conformation of propylcyclohexane. Also name the conformation of the ring, and the position of the propyl substituent. (10pts)
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15) State two facts about a σ bond, and two facts about a π bond. (4pts) b) State two characteristics of an E2 reaction. (2pts)
c) State two characteristics of an SN1 reaction. (2pts)
d) Define structural isomers, and stereoisomers. Provide an example of both types. (6pts)
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16) Give the reagents for 5 of the 6 following reactions of methylcyclohexene. (15pts)
O
Br
OH
Br
BrOH
16b) Write the mechanism for one of the above reactions. (10pts)
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17a) Give the products in 5 of the 6 following transformations. (15pts)
OH
PCC
H2CrO4
PBr3
1) Na2) CH3CH2CH2Br
1) Pyridine, Tos-Cl
H2SO4
H3C-C C- +Na2)
17b) Write the mechanism for one of the above reactions. (10pts)
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***BONUS QUESTION (1 pt per correct answer, maximum = 6)*** Draw all the different isomers of C5H10 that contain zero π bonds.
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