org. chem. Flashcards
(28 cards)
- Predict the product of the following reaction sequence. Ethyne + 1) excess NaNH2 2) excess I-CH2-(CH2)2-CH3–
a. 6-iodo-1-hexyne
b. 1-hexyne
c. 5-decyne
d. 1-iodo-1-hexene
b. 1-hexyne
The metal-catalyzed addition of hydrogen to an alkene occurs in what fashion?
a. Syn
b. Anti
c. Mixture of syn and anti
d. neither syn nor anti
d. neither syn nor anti
Pyridinium chlorochromate (PCC) ia a commercially available reagent that provides Cr6+ ( as CrO3), and does not contain water. It is useful for oxidizing primary alcohols to aldehydes, and secondary alcohols to ketones. Which of the following compounds does not give an aldehyde upon reaction with PCC?
a. benzyl alcohol
b. cyclopentylmethanol
c. 2,2-dimethyl-1-butanol
d. 3-methyl-3-pentanol
d. 3-methyl-3-pentanol
Which of the following statements best describes the most stable conformation of trans 1,3-dimethylcyclohexane?
a. Both methyl groups are axial
b. Both methyl group are equatorial
c. one methyl group is axial, the other isequatorial
d. The molecule is severely strained andcannot exist
c. one methyl group is axial, the other isequatorial
Upon hydrogenation, which of the following alkenes releases the least heat per mole
a. 3,4-dimethyl-1-hexene
b. (Z)-3,4-dimethyl-2-hexene
c. (E)-3,4-dimethyl-2-hexene
d. (Z)-3,4-dimethyl-3-hexene
e. . (E)-3,4-dimethyl-3-hexene
e. . (E)-3,4-dimethyl-3-hexene
Carbon-carbon double bonds do not undergo rotation as do carbon-carbon single bonds. The reason is that
a. the double bond is much stronger and thus more difficult to rotate
b. overlap of the sp2 orbitals of the carbon-carbon sigma bond would be lost
c. overlap of the p orbitals of the carbon-carbon pi bond would be lost
d. The shorter bond length of the double bond makes it more difficult for the attached
groups to pass one another
e. The statement is incorrect-rotation around double bonds does occur
c. overlap of the p orbitals of the carbon-carbon pi bond would be lost
- What is the major product from the acid-catalyzed hydration of 2-methyl-2-pentene?
a. 2-methylpentane
b. 2-methyl-1-pentanol
c. 2-methyl-2-pentanol
d. 2-methyl-3-pentanol
e. 1- methoxypentane
c. 2-methyl-2-pentanol
How many electrons are involved in a carbon-carbon triple bond?
a. 1
b. 2
c. 3
d. 4
e. 6
e. 6
Which of the following is a correct statement about the carbon-carbon triple bond in an
alkyne?
a. composed of one sigma bond and one pi bond
b. composed of two sigma bond and one pi bond
c. composed of one sigma bond and two pi bond
d. composed of two sigma bond and two pi bond
e. composed of one sigma bond, one pi bond and one delta bond
c. composed of one sigma bond and two pi bond
Which of the following is not used as primary standard for sodium hydroxide solutions?
a. KHP
b. Benzoic Acid
c. Sulfuric Acid
d. Potassium biodate
c. Sulfuric Acid
Which of the following nonpolar molecules should have the highest boiling point?
a. SF1
b. CH4
c. CO2
d. N2
a. SF1
- The least reactive towards electrophilic aromatic substitution
A.
Which of the following reactions is associated with the inversion of configuration of a chiral substrate?
a. Nucleophilic Substitution Bimolecular
b. Elimination Unimolecular
c. Nucleophilic Acyl Substitution
d. Free radical Addition
a. Nucleophilic Substitution Bimolecular
Which of the following is an essential fatty acid
a. palmitic acid
b. stearic acid
c. lauric acid
d. linolenic acid
d. linolenic acid
Which of the following is the strongest Brønsted base?
C.
Which of the following reactions would not be useful for converting 4,4-diethylcyclohexanone into 1,1-diethylcyclohexane?
a. Wolff-Kischner reduction (N2H4, strong base & heat)
b. Clemmensen reduction (Zn/Hg, acid & heat)
c. Thioacetal reduction (i HSCH2CH2SH & BF3; ii H2 + Raney Ni)
d. LiAlH4 in THF & heat
d. LiAlH4 in THF & heat
A C5H8 hydrocarbon is reacted with BH3 in THF, followed by oxidation with alkaline hydrogen peroxide. Treatment of the resulting product with PCC in CH2Cl2 produces a
chiral ketone, formula C5H8O. What hydrocarbon best fits these facts?
a. 1-methylcyclobutene
b. methylenecyclobutane
c. vinylcyclopropane
d. cyclopentene
a. 1-methylcyclobutene
Determine the double bond stereochemistry (E or Z) for the following molecules.
a. A: E, B: E
b. A: Z, B: Z
c. A: E, B: Z
d. A: Z, B:E
d. A: Z, B:E
Which of the following is/are chiral?
a. 1,2 and 3
b. 1 and 2
c. Only 1
d. Only 2
b. 1 and 2
How many chiral centers are there in 3-bromo-2-pentanol ?
a. 2
b. 3
c. 4
d. 1
a. 2
What is the stereochemistry of the following compound?
a. R
b. S
c. E
d. Z
c. E
How many gauche are present in cis-1,4-dimethylcyclohexane?
a. 1 gauche
b. 2 gauche
c. 3 gauche
d. 4 gauche
b. 2 gauche
Which of the following used as a suffix of carbaldehyde in naming?
a. - CHO
b. = CHO
c. =-CHO
d. d. all of these
a. - CHO
Conjugated alkenes are characterized by
a. Alternating pi and sigma bonds.
b. Adjacent pi bonds.
c. pi bonds separated by two or more sigma bonds.
d. A cyclic system containing 6pi bonds.
a. Alternating pi and sigma bonds.
