Chapter 7 Flashcards
What is the IUPAC name for the following alkyne?
A) 5-Bromo-2-heptyne
B) 3-Bromo-5-heptyne
C) 2-Bromo-2-methyl-4-hexyne
D) 5-Bromo-5,5-dimethylhexyne
E) 5-Bromo-5-methyl-2-hexyne
Answer: E
How many distinct terminal alkynes exist with a molecular formula of C5H8?
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: B
How many distinct internal alkynes exist with a molecular formula of C6H10?
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: C
What is the common name for the following alkyne?
A) neohexyne
B) trimethylpropyne
C) trimethylacetylene
D) tert-butylacetylene
E) isopropylacetylene
Answer: D
Write structures and give IUPAC names for all alkynes with molecular formula C5H8.
Give the IUPAC name for (CH3)2C(CH2CH3)CCCH(CH3)2.
Answer: 2,5,5-trimethyl-3-heptyne
Give the IUPAC name for HCCCH2CH2CH3.
Answer: 1-pentyne
Give the IUPAC name for BrCH2CH2CCCH2CH3.
Answer: 1-bromo-3-hexyne
Draw an acceptable structure for acetylene.
Answer: H–C C–H
Draw an acceptable structure for 3-sec-butyl-1-heptyne.
Draw an acceptable structure for 2-hexyne.
Provide the systematic name of the compound shown.
Answer: 5,6,6-trimethyl-1-heptyne
Give the systematic name for the alkyne Cl3CCH2CH2CCCH3.
Answer: 6,6,6-trichloro-2-hexyne
Provide the structure of all distinct terminal alkynes with a molecular formula of C6H10.
Name the following compound.
A) 3-heptyn-6-ol
B) 3-hepten-6-ol
C) 4-hepten-2-ol
D) 4-heptyn-2-ol
E) 4-heptan-2-ol
Answer: D
Name the following compound.
Answer: cis-4,5-dimethyl-4-hepten-2-yne
or (Z)-4,5-dimethyl-4-hepten-2-yne
Provide an acceptable name for the compound shown.
Answer: 7,7-dichloro-5,5-dimethyl-3-heptyne
or
7,7-dichloro-5,5-dimethylhept-3-yne
Give the IUPAC name for the following compound.
A) isoprene
B) 3-methyl-1,3-butadiene
C) 2-methyl-1,3-butadiene
D) 2-methyl-2,3-butadiene
E) isobutadiene
Answer: C
What is the IUPAC name for the following compound?
A) cis, trans-2, 4-heptadiene
B) 2Z,4Z-2, 4-heptadiene
C) cis, cis-2, 4-heptadiene
D) trans, trans-2, 4-heptadiene
E) 2E,4E-2, 4-heptadiene
Answer: A
Give the systematic name of the compound shown below.
Answer: 1,7-dimethyl-1,3-cycloheptadiene
Give the systematic name of the compound shown below.
Answer: (S)-5-methyl-5-hexen-2-ol
Name the following compound.
Answer: (2E,4Z)-2,4-hexadiene
or trans, cis-2,4-hexadiene
or (2Z,4E)-2,4-hexadiene
or cis, trans-2,4-hexadiene
Provide the structure of (2E,4E)-2-chloro-2,4-octadiene.
Provide the systematic name of the compound shown.
Answer: (E)-5-methyl-5-hepten-1-yne
Which of the following improperly describes the physical properties of an alkyne?
A) relatively nonpolar
B) nearly insoluble in water
C) less dense than water
D) insoluble in most organic solvents
Answer: D
What are the hybridizations of the carbon atoms numbered 1 and 2 respectively in the following structure?
A) sp3, sp2
B) sp2, sp2
C) sp, sp
D) sp2, sp
E) sp, sp2
Answer: D
Which of the following statements is not true about propyne, HC C=-CH3?
A) It contains six sigma bonds.
B) It contains three pi bonds.
C) The H—C—H bond angle is about 109.5°.
D) The C—C—C bond angle is 180°.
E) The pi bond is weaker than the sigma bond.
Answer: B
The carbon-carbon triple bond of an alkyne is composed of
A) three σ bonds.
B) two σ bonds and one π bond.
C) one σ bond and two π bonds.
D) three π bonds.
Answer: C
What are the hybridizations of the carbon atoms numbered 1 and 2 in the structure below?
A) sp3, sp2
B) sp2, sp2
C) sp2, sp
D) sp, sp
Answer: D
What two atomic orbitals or hybrid atomic orbitals overlap to form the carbon-carbon σ bond in ethyne?
A) sp3—sp3
B) p—p
C) sp2—sp2
D) s—s
E) sp—sp
Answer: E
Which of the following statements correctly describes the general reactivity of alkynes?
A) An alkyne is an electron-rich molecule and therefore reacts as a nucleophile.
B) The σ bonds of alkynes are higher in energy than the π bonds and are thus more reactive.
C) Unlike alkenes, alkynes fail to undergo electrophilic addition reactions.
D) Alkynes are generally more reactive than alkenes.
E) Alkynes react as electrophiles, whereas alkenes reacts as nucleophiles.
Answer: A
Although you might expect 1-propyne to be more reactive than 1-propene in electrophilic addition reactions, the reverse is true. Explain this using your knowledge of the mechanism of electrophilic additions to both alkynes and alkenes.
What is the major product of the following reaction?
Answer: B
Which of the following is the best synthesis of 2, 2-dibromopropane?
Answer: C
In the addition of hydrogen bromide to alkynes in the absence of peroxides, which of the following species is believed to be an intermediate?
A) vinyl anion
B) vinyl cation
C) vinyl radical
D) carbene
E) bromonium ion
Answer: B
________ is produced when 1 equivalent of HBr is added to 1-hexyne.
A) 2-bromo-1-hexene
B) E-1-bromo-1-hexene
C) Z-1-bromo-1-hexene
D) A mixture of E and Z isomers of 1-bromo-1-hexene
E) E-2-bromo-2-hexene
Answer: A
Which of the following compounds is the major product when 1-hexyne is treated with excess HBr?
A) 1,1-dibromohexane
B) 1,1-dibromohexene
C) 1,2-dibromohexene
D) 1,2-dibromohexane
E) 2,2-dibromohexane
Answer: E
Provide the structure of the major organic product(s) in the reaction below.
Provide the structure of the major organic product of the following reaction.
Provide the structure of the major organic product of the following reaction.
Provide the major organic product in the reaction below.
Provide the major organic product in the reaction below.
Provide the major organic product in the reaction below.
Provide the major organic product in the reaction below.
Provide the major organic product in the reaction below.
Give the major organic product for the reaction.
Answer: D
Give the major organic product for the reaction.
Answer: E
Provide the structure of the major organic product that results when 2-butyne is treated with 1 equivalent of HCl.
Provide the structure of the major organic product that results when 2-butyne is treated with 2 equivalents of HCl.
Answer: CH3CH2CCl2CH3
Provide the structure of the major organic product that results when 2-butyne is treated with 1 equivalent of Br2.
Which of the following are enol forms of 2-butanone?
Answer: E
Which of the following is the final and major product of this reaction?
A) I
B) II
C) III
D) IV
E) V
Answer: A