How many signals appear in the proton-decoupled 13C NMR spectrum of 2-methyl-2-butene?
D. 5
How many signals appear in the proton-decoupled 13C NMR spectrum of 2-methylbutane?
C. 4
WHich is the furthest downfield?
iii
Which has the highest d-value in the 1H-NMR spectrum?
iii
Which of the following combinations of peaks appears in the 1H NMR spectrum of 2,3-dimethylbutane?
D. a doublet and a septet
The 1H-NMR spectrum of compound X shows methyl and methylene signals in the intensity ratio 3:1. Which compound is X?
A. (CH3)2CBr-CH2Br
Which one of the following pairs of protons are enantiotopic?
E. the allylic protons in allyl bromide
What is the multiplicity of the -OH peak of ethanol that contains a trace amount of acid?
E. singlet
How many kinds of chemically and magnetically nonequivalent hydrogen nuclei are there in 2-methylpropene?
2
Consider a monochlorocyclohexane that is polydeuterated such that all hydrogen atoms were replaced by deuterium except for the one H-atom at C-1. Which statement best describes the low-temperature (-100 °C) 1H-NMR spectrum of this molecule? [Assume that the H and D are not coupled.]
two singlets with different intensities
Which of the following is the reactive intermediate formed in the electrophilic bromination of toluene upon treatment with Br2, FeBr3?
3
Which of the following undergoes the most rapid sulfonation upon treatment with fuming sulfuric acid?
A. benzene
Which of the following sets of substituents are all activating groups in electrophilic aromatic substitution reactions?
B. -CH3, -NH2, -OCH3
4
Which undergoes the most rapid substitution with hydroxide?
3
Which mechanism accounts for the reaction of 4-bromotoluene with sodium amide to form a mixture of 3- and 4-aminotoluene?
nucleophilic aromatic substitution by elimination/addition
This substituted benzenes would react ____ with HNO3/H2SO4?
fastest
all of the above
Why do reagents such as AlCl3 and AlBr3 make good catalysts for Friedel-Crafts alkylations and acylations?
They are electron deficient and promote the removal of a halogen atom to form the electrophile.
