Chem 2062 - Spring 2007 – EXAM #1
Name __________________________
1. (6 pts, 3 each) Give the common name of the following compounds
a)
b)
CH3
O
CH3
_________________________
____________________________
2. (6 pts, 3 each) Give the IUPAC name of the following compounds. Be sure to use E/Z, R/S or
cis/trans prefixes if necessary.
a)
b)
O
HO
O
Cl
H
H
Cl
O
_______________________________
_________________________
3. (4 pts, 2 each) Classify the following substances as either aromatic or nonaromatic.
a)
b)
H
N
N
N
N
________________
___________________
4. (3 pts) Rank the order of expected max for these substances in their UV/Vis spectra.
I)
O
O
II)
CH2
CH2CH3
OCH2CH3
OCH2CH3
III)
CH2CH3
O
CH2CH3
CH3CH2OH
a) longest max I > II > II shortest
b) longest max II > III > I shortest
c) longest max I > III > II shortest
d) longest max II > I > III shortest
e) longest max III > I > II shortest
5. (7 pts) Explain briefly how an mass spectrometer works. Explain how a molecule is ionized in
a mass spectrometer and how and why the different ions can be separated. You can use a diagram if
you would like to help explain your answer.
6. (6 pts) The low resolution mass spectrum of 2-methyl-2-butanol (MW = 88) shows 16 peaks.
The molecular ion is absent. The two largest peaks in the spectrum are m/z = 73 and 59.
a) Show a fragmentation mechanism for the formation of the species responsible for these
peaks, and b) propose a structure for each of the species.
OH
CH3CH2C CH3
CH3
7. (6 pts) Suggest a synthesis for the following alcohol from an aldehyde or ketone and an
appropriate Grignard reagent. Show how you would form the Grignard reagent as well.
OH
H
CH3
8. (6 pts) Pyridine exhibits a UV transition of the type n
* at 270 nm. In this transition, one
of the unshared electrons on the nitrogen is promoted from a nonbonding molecular orbital to a *
MO. What is the effect on this UV peak if the pyridine is protonated? EXPLAIN WHY YOU
CHOSE YOUR ANSWER.
+
H+
N+
N
H
a) The UV peak would be shifted to a longer wavelength
b) The UV peak would be shifted to a shorter wavelength.
c) The UV peak would stay at the same wavelength.
9. (4 pts) Which M + 1 peak is incorrect relative to the M+ peak for the compound indicated?
a)
M + 1 = approx. 8% of M+
OMe
Br
M + 1 = approx. 98% of M+
b)
Br
c) C27H46O
M + 1 = approx. 30% of M+
d) CH3Cl
M + 1 = approx. 1% of M+
e) Si(CH3)4
M + 1 = approx. 4% of M+
10. (7 pts) Propose a synthesis for the following compound starting with benzene.
CH3
CH3C CH3
NO2
11. (6 pts, 3 each) For each of the following pairs of compounds, explain how you would be able to
distinguish between them by infrared spectroscopy.
a)
NH2
OMe
and
O
O
b)
O
O
and
H3C
H3C
CH3
H
H
12. (16 pts, 4 each) Give the structures for the major product or the reagents needed for the
following transformations. If no reaction occurs, write NO RXN.
a)
HO H
O
OMe
OMe
O
O
b)
O
H3C
NH
O
1)
Cl
AlCl3
2) H2O
c)
CN
Cl2
FeCl3
d)
O
1) CH3CH2Li
2) H3O+
13. (12 pts) a) Explain why the major product formed in the following reaction is the ortho, para
products and not the meta product. BE SURE TO INCLUDE THE RESONANCE STRUCTURES
OF THE INTERMEDIATE FORMED IN THE RXN AS PART OF YOUR EXPLANATION.
b) Explain why anisole (the starting material below) undergoes electrophilic aromatic substitution
MORE readily than benzene itself.
OMe
OMe
OMe
Br2
Br
+
FeBr3
Br
14. (2 pts) Buckminster Fullerene, or bucky balls, are a recently discovered allotrope of carbon.
How many carbons atoms are in one “bucky ball”?
a) 1,000
b) 2
c) 60
d) 10
e) 6.022 x1023
15. (2 pts) Which of the following will not undergo a McClafferty rearrangement?
a) 2-pentanone
b) 2-butanone
c) 2-hexanone
d) 2-octanone
e) 2-heptanone
16. (8 pts, 4 each) For each of the IR spectra shown, indicate which of the compounds listed is
responsible for the spectrum and explain your reasoning.