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Practice Exam #2 CHEM 256 – Organic Chemistry II
Prof. Bastin Spring 2014
Name ___________________________ Provide clear, concise answers using unambiquous, carefully drawn structures (where appropriate) for all of the questions. Good luck and enjoy!
1) _______/10 pts 2) _______/10 pts
3) _______/10 pts
4) _______/10 pts Total: ________/100 pts 5) _______/10 pts
6) _______/10 pts
7) _______/8 pts 8) _______/10 pts 9) _______/12 pts 10) _______/10 pts
Bastin – Practice Exam #3 Chem 256 - Spring 2014
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1) (10 pts) Provide structures for the following compounds.
a) 1-Bromo-2-chloro-4-ethylbenzene
b) 3,5-dinitrotoluene c) 3-aminostyrene d) m-propylbenzaldehyde e) o-bromoaniline
Bastin – Practice Exam #3 Chem 256 - Spring 2014
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2) (10 pts) Provide either common or IUPAC names for the following compounds?
a)
b)
c)
d)
e)
NO2
Cl
CH2Br
OCH3
Ph
OH
NH2
Cl
Cl
Cl
Cl
Cl
OH
Bastin – Practice Exam #3 Chem 256 - Spring 2014
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3) (10 pts) Write a mechanism for the Friedel-Crafts alkylation of benzene using isopropyl bromide and AlBr3.
4) (10 pts) Predict whether the following molecules would be aromatic or non-aromatic.
Explain your reasoning.
B
H
Bastin – Practice Exam #3 Chem 256 - Spring 2014
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5) (10 pts) Draw the product(s), if any, of the following reactions. Indicate stereochemistry where relevant.
a)
b)
c)
d)
e)
OH
CrO3H2SO4
OH
+ H3PO4
KMnO4
OH
NH2
Br2FeBr3
OH
CHO
Br2FeBr3
Bastin – Practice Exam #3 Chem 256 - Spring 2014
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6) (10 pts) Provide the reagents needed to bring about the following transformations.
a)
b)
(c)
(d)
(e)
NH2NH2
Cl
OH
OH
OH
OH
SO3H
Br H3N
O
Bastin – Practice Exam #3 Chem 256 - Spring 2014
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7) (8 pts) Write resonance forms for the following ion.
8) (10 pts) How do you account for the fact that N-phenylacetamide is less reactive toward electrophilic aromatic substitution than aniline?
NH
C CH3
O
NH2
N-Phenylacetamide Aniline
Bastin – Practice Exam #3 Chem 256 - Spring 2014
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9) (12 pts) Compound E (C8H10O2) is a neutral solid. Following are IR and 1H-NMR spectra of compound E. Deduce the structure of compound E and justify your structure by assigning all the appropriate peaks in the IR and NMR spectra and providing a short narrative describing what structural information each piece of data provided.
Bastin – Practice Exam #3 Chem 256 - Spring 2014
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10) (10 pts) Provide a synthesis for the following molecule from benzene, inorganic reagents of your choice, organic reagents containing no more than four carbons, and pyridine.
OCH3
NO2
NO2
Bastin – Practice Exam #3 Chem 256 - Spring 2014
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degrees of unsaturation = (#C atoms) – (#H atoms)/2 + (#N atoms)/2 + 1
Bastin – Practice Exam #3 Chem 256 - Spring 2014
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Functional Group Frequency (cm-1) Intensity and Comments Alkanes
C–H C–C
2980-2850 1480-1420
medium to strong medium
Alkenes =C–H stretch =C–H bend C=C
3150-3000 980-960 (trans) 730-665 (cis) 1680-1600
medium; very weak for trans strong strong weak to medium
Alkynes ≡C–H C≡C
3350-3300 2260-2100
strong weak to medium
Alkyl halides C–Cl C–Br C–I
800-600 600-500 500
strong strong strong
Alcohols O–H C–O
3650-3300 1350-1050
strong and broad strong
Amines N–H C–N
3500-3100 ~1200
medium and strong; 1° amines-2 bands; 2° amines-1 band medium
Aromatics C–H stretch C–H bend C=C
3080-3020 900-730 1650-1580
weak to medium strong weak to medium
Carbonyls (C=O) Ketones/aldehydes Esters Amides Acids Acid Anhydride Acid Chlorides
1730-1700 1750-1735 1680-1630 1730-1700 1850-1740 1820-1770
strong strong; also has C–O stretch strong; 1° and 2° amides also have N-H stretch strong; also has O–H stretch strong; doublet strong
Nitrile (C≡N) 2200-2250 medium