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Practice Exam 3
1. (19 pts)
(a) Circle the group with the higher Cahn Ingold Prelog priority in each of the following pairs (6 pts.).
CH2
and CHC
and
CH2 and
NCH2 CH3
CH3
1)
2)
3)
Br
OH
H3C
NHCH3
(b) The sex attractant of the codline moth is the 2Z, 6E stereoisomer of the molecule below. Write thestructure of this substance in a way that clearly shows its stereochemistry. (4 pts).
CH3CH2CH2C=CHCH2CH2C=CHCH2OH
CH3 CH2CH3
(c) Provide the IUPAC names for the following compounds. Be sure to designate E or Zstereochemistry for part (i) (6 pts).
(i) (ii)
Cl
OH
(d) Draw a structure for the following molecule (3 pts):
4-methyl-4-penten-2-ol
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2. (38 pts) Draw the principal organic product expected from each of the following reactions. If more than oneproduct is expected, be sure to indicate which is the major product. Pay particular attention toSTEREOCHEMISTRY AND REGIOCHEMISTRY where appropriate.
(a)
CH3
Br
CH3
HK+ -OC(CH3)3
HOC(CH3)3
(b)H2SO4
HOC(CH2CO2H)2
CO2H
citric acid
(c)
CH3CH2O-Na+
CH3CH2OH
CH3Br
(d)
KHSO4
heat
HO CN
H3CO
(e)
2-methyl-2-buteneperoxides
HBr
(f)
H2
Pt
CH3
CH3
Which reaction part above involves a non-Zaitsev elimination?_________ (2 pts)
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(g)
H2O
Br2CH3
(h)O
OO
H
Cl
(i)
HCl
(j)
H2SO4
(catalyticamount)
CH3
H2O
(k)CH3
CH3
B2H6 H2O2
NaOH
(l)
1. O3
2. (CH3)2S
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3. (13 pts ) Complete the following questions:(a)The carbocation below has the potential to rearrange to a more stable carbocation. Write the structure of therearranged carbocation (3 points).
(CH3)2CH CH CH3
(b) Draw out the alkenes you would expect to get from the E2 elimination of 2-bromo-2-methylpentane (4pts).
(c) The reaction of 1-butene with bromine, Br2, in aqueous solution gives primarily 1-bromo-2-butanol.Identify the nucleophilic species in the reaction (3 pts). A. Br2B. Br C. H2OD. HOBr
(d) Which of the following alkenes is expected to have the highest heat of hydrogenation (circle the correctanswer (3 pts)?
A. 1-penteneB.trans-2-penteneC.cis-2-penteneD.2-methyl-2-butene
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4. (16 pts)
(a) (9 pts) Compounds A is an alcohol of molecular formula C6H14O. On being heated with sulfuric acid, a majoralkene B and a minor alkene C are formed. Ozonolysis, followed by treatment of the ozonide with dimethylsulfide,of major alkene B gives acetone (structure shown). What are the structures of compounds A and B and C. Brieflyexplainhow you arrived at your answer (you can answer this by showing reactions).
H3C CH3
O
acetone
Is acetone and aldehyde or ketone? ________________ (1 point)
(b) (6 pts) Outline a sequence of reactions that would be suitable for the preparation of the following compound fromindicated starting material and any needed reagents. The synthesis will require more than one step.
1-bromo-2-propanol from 2-propanol
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5. Mechanisms(14 pts)(a) Provide a stepwise mechanism, using arrows to show electron movement, to account for the formation of the
product in the following reaction. (6 pts)
IBr
Br
I
(b) Provide a stepwise mechanism, using arrows to show electron movement, to account for the formation of theproducts in the following reaction. (8 pts)
+H3O
+OH
+
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