Organic Chemistry Chapter 9

39) To a solution of propyne in diethyl ether, one molar equivalent of CH3Li was added and the resulting mixture was stirred for 0.5 hour. After this time, an excess of D2O was added. Describe the major organic product(s) of this reaction. A) CH3C≡CD + CH4 B) CH3C≡CCH3 C) CD3C≡CD3 D) CH3C≡CCD3 E) CH3C≡CD + CH3D

A) CH3C≡CD + CH4

61) How many distinct alkynes exist with a molecular formula of C4H8? A) 0 B) 1 C) 2 D) 3 E) 4

A) 0

27) A mixture of hept-1-yne, hept-2-yne, and hept-3-yne was hydrogenated in the presence of a platinum catalyst until hydrogen uptake ceased. If one assumes that the hydrogenation went to completion, how many different seven-carbon hydrocarbons were produced? A) 1 B) 2 C) 3 D) 6 E) 8

A) 1

80) What is the major organic product that results when 3-heptyne is hydrogenated in the presence of Lindlar's catalyst? A) 2-heptyne B) (Z)-2-heptene C) (Z)-3-heptene D) (E)-3-heptene E) heptane

C) (Z)-3-heptene

60) How many distinct alkynes exist with a molecular formula of C4H6? A) 0 B) 1 C) 2 D) 3 E) 4

C) 2

66) Which of the following reagents should be used to convert an internal alkyne to an α-diketone? A) KMnO4, H2O, neutral B) O3 then H2O C) Sia2BH then H2O2 D) Na, NH3 E) HgSO4, H2SO4

A) KMnO4, H2O, neutral

85) What class of organic product results when 1-heptyne is reacted with disiamylborane followed by treatment with basic hydrogen peroxide? A) aldehyde B) ketone C) diol D) ether E) carboxylic acid

A) aldehyde

90) Which of the following bases are sufficiently strong to deprotonate a terminal alkyne with an equilibrium constant greater than 1? 1) sodium methoxide 3) n-butyl lithium 2) lithium diisopropyl amide 4) phenylmagnesium bromide A) 1, 2, and 3 B) 2, 3 and 4 C) 2 and 3 D) 3 and 4 E) 1, 2, 3 and 4

B) 2, 3 and 4

20) Which of the species below is less basic than acetylide? A) CH3Li B) CH3ONa C) CH3MgBr D) both A and C E) all of the above

B) CH3ONa

63) Which of the following reagents should be used to convert hex-3-yne to (E)-hex-3-ene? A) H2, Pt B) Na, NH3 C) H2, Lindlar's catalyst D) H2SO4, H2O E) HgSO4, H2O

B) Na, NH3

84) What class of organic product results when 1-heptyne is treated with a mixture of mercuric acetate in aqueous sulfuric acid? A) aldehyde B) ketone C) diol D) ether E) carboxylic acid

B) ketone

32) In the addition of hydrogen bromide to alkynes in the absence of peroxides, which of the following species is thought to be an intermediate? A) vinyl anion B) vinyl cation C) vinyl radical D) carbene E) none of the above

B) vinyl cation

38) Among the compounds water, but-1-yne, but-2-yne, and ethane, which are stronger acids than ammonia? A) but-1-yne and ethane B) water and but-1-yne C) water and ethane D) but-1-yne and but-2-yne

B) water and but-1-yne

12) How many distinct internal alkynes exist with a molecular formula of C6H10? A) 1 B) 2 C) 3 D) 4 E) 5

C) 3

64) Which of the following reagents should be used to convert hex-3-yne to (Z)-hex-3-ene? A) H2, Pt B) Na, NH3 C) H2, Lindlar's catalyst D) H2SO4, H2O E) HgSO4, H2O

C) H2, Lindlar's catalyst

82) What is the major organic product that results when 3-heptyne is treated with sodium metal in ammonia? A) 2-heptyne B) (Z)-2-heptene C) (Z)-3-heptene D) (E)-3-heptene E) heptane

D) (E)-3-heptene

15) 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 E) boiling point nearly the same as an alkane with similar carbon skeleton

D) insoluble in most organic solvents

13) The carbon-carbon triple bond of an alkyne is composed of __________. A) three σ bonds B) three π bonds C) two σ bonds and one π bond D) one σ bond and two π bonds

D) one σ bond and two π bonds

29) In the reduction of alkynes using sodium in liquid ammonia, which of the species below is not thought to be an intermediate in the commonly accepted mechanism? A) vinyl anion B) vinyl radical C) radical anion D) vinyl cation

D) vinyl cation

83) What is the major organic product that results when 1-heptyne is treated with 2 equivalents of HBr? A) 2,3-dibromo-1-heptene B) 2,3-dibromo-2-heptene C) 1,2-dibromoheptane D) 2,2-dibromoheptane E) 1,1-dibromoheptane

D) 2,2-dibromoheptane

58) How many moles of oxygen are required in the complete combustion of 1 mole of acetylene? A) 1 B) 1.5 C) 2 D) 2.5 E) 3

D) 2.5

41) __________ is produced when 1 equivalent of HBr is added to hex-1-yne in the presence of peroxides. A) 2-Bromohex-1-ene B) E-1-Bromohex-1-ene C) Z-1-Bromohex-1-ene D) A mixture of E and Z isomers of 1-bromohex-1-ene E) E-2-Bromohex-2-ene

D) A mixture of E and Z isomers of 1-bromohex-1-ene

42) Which of the alkyne addition reactions below involve(s) an enol intermediate? A) hydroboration/oxidation B) treatment with HgSO4 in dilute H2SO4 C) hydrogenation D) both A and B E) none of the above

D) both A and B

26) When 2,2-dibromobutane is heated at 200°C in the presence of molten KOH, what is the major organic product? A) 1-bromobut-1-yne B) 1-bromobut-2-yne C) but-1-yne D) but-2-yne E) but-1-ene

D) but-2-yne

92) Complete the transformation below by indicating the necessary sequence of reagents. A) 1) DBr 2) BD3 3) H2O2 / NaOH B) 1) D2 / Pd, BaSO4, quinoline 2) Br2 / H2O C) 1) Na / ND3 2) Br2 3) H2O D) 1) Na / ND3 2) Br2 / H2O E) 1) Br2 / H2O 2) D2 / Pd, BaSO4, quinoline

B) 1) D2 / Pd, BaSO4, quinoline 2) Br2 / H2O

11) How many distinct terminal alkynes exist with a molecular formula of C5H8? A) 1 B) 2 C) 3 D) 4 E) 5

B) 2

14) In trans-hept-4-en-2-yne the shortest carbon-carbon bond is between carbons __________. A) 1 and 2 B) 2 and 3 C) 3 and 4 D) 4 and 5 E) 6 and 7

B) 2 and 3

88) The correct IUPAC name for the following structure is __________. A) (Z) 4-isopropyl-4-hepten-2-yne B) (E) 4-isopropyl-3-hepten-5-yne C) (E) 4-isopropyl-4-hepten-2-yne D) (Z) 4-isopropyl-3-hepten-5-yne

C) (E) 4-isopropyl-4-hepten-2-yne

89) What is the correct IUPAC name for the following compound? A) 4-(1-bromopropyl)-1-hexen-5-yne B) 4-allyl-5-bromo-1-hexyne C) 3-(1-bromopropyl)-5-hexen-1-yne D) 5-bromo-4-ethynyl-1-heptene

C) 3-(1-bromopropyl)-5-hexen-1-yne

81) What is the major organic product that results when 3-heptyne is subjected to excess hydrogen and a platinum catalyst? A) 2-heptyne B) (Z)-2-heptene C) (Z)-3-heptene D) (E)-3-heptene E) heptane

E) heptane