O Chem 1 Final Exam 2 and 3
which is a meso compound
(2R,3S)-2,3-dibromobutane
select the correct name of the following compound (CH3 on 3 wedge, CH3 on 4 dashed)
(3R,4S)-3,4-dimethlyheptane
Select the name of the following compound (Cl on 3 wedge)
(S)-3-chloro-6-ethyloctane
the highest priority group using the Cahn-Ingold-prelog R and S nomenclature is
--CH2OH
In the lowest energy conformation of the compound below, how many alkyl substituents are axial
0
How many tertiary (3) hydrogens and primary (1) carbons in the following alkane, respectively
1 and 7
Identify the most appropriate reason for the instability of axial isopropycyclohexane
1,3 diaxial interactions
Which of the following alkyl halides reacts the fastest in an Sn2 reaction
1-bromo-4methlypentane
select the name of the following compound (begins with Cl and 2 lines up on 3)
1-chloro-2,2-dimethylbutane
Which of the following alkyl halides reacts the fasted in an SN2 reaction
1-iodobutane
How many quaternary (4) carbons and secondary (2) hydrogens in the following alkane respectively
2 and 2
enantiomeric excess % (ee%) of (S)-2-iodobutane in a mixture is 50%, what is the Toal amount of (R)-2-iodobutane in the mixture
25%
In the lowest energy conformation of the compound below, how many alkyl substituents are equatorial
3
Select the name of the following compound
3-bromo-2,3-dimethylpentane
IUPAC name of the following alkane
4-ethyl-5-methlyoctane
Name a different alkane
4-isopropyl-2-methylheptane
Name of the alkane
4-tert-butyl-2-methylheptane
what is the common name of the following alkyl group
5 carbons, one pointed up, A sec-butyl
enantiomeric excess % (ee%) of (S)-2-iodobutane in a mixture is 20% what is the total amount of (S)-2-iodobutane in the mixture
60%
Enatiomeric excess % (ee%) of (S)-2-iodobutane in a mixture is 40%. what is the total amount of (S)-iodobutane in the mixture
70%
indicate the statement that is FALSE about meso compounds
A meso compound is chiral
Which of the following is a Lewis acid
AlCl3
the structures below are drawn using different conventions, how are the represented compounds related
Diasteromers
which line angle drawing best represents the Newman projection shown below
B, CH3 and Cl on wedge, H CH3 on dashed
select the product of the following reaction 1)NaBr 2)NaCn
B, CN on a wedge bond
Which of the following structures has a different configuration from the other three
B, all R groups are connected from the bottom, H on top
Which of the following compounds is a bridged bicycle
Bicyclo [2.2.1] heptane
Select the product of the following reaction
Br leaves, two step reaction, N3 is on other side
Select the arrangement of the alkanes in order of increasing boiling point
Branched 2 and 4 C's on the last one
given the structure of aspartame (Nutrasweet) below, the configuration of the indicated chiral centers are
C3 is R and C6 is S
Select the best leaving group
CF3SO3
Which of the following structures has a different configuration from the other three
CH2 is solo on bottom, I
in the lowest energy conformation of the compound below, which alkyl substituents is(are) axial
CH3
Which of the following structures is considered a gauche conformer
CH3 CH3 beside each other
Select the most acidic compound
CH3CF2COOH
Select the polar Protic solvents
CH3CN and DMF
Order of chemical species from least to most basic
CH3S- < CH3O < NH2-
The highest priority group using the Cahn-Ingold-prelog R and S nomenclature is
CO2H
identify the electrophilic atom in the following reaction CH3CH2CH2CH2Br + NaN3
Carbon
Which of the following compounds has the lowest heat of combustion (most stable)
Ch3 wedge and Ch3 striped across
rank the following compounds in order of decreasing acidity, putting the most acidic first
ClCH2CH2OH > CH3CH2OH > CH3CH2NH2
Polar aprotic solvents
DMSO and CH3CO2H
Which is the best representation for electron pushing arrows for an Sn2 reaction
D, Br bond breaks and OCH3 forms where Br broke off
Identify the cis stereoisomer from the following structures
D, Hydrogen on the bottom
the following diagram represents the boat conformation for cyclohexane. identify the most appropriate reason for the instability of boat conformation
Flagpole interactions
which of the statements below correctly describes the conformations of acyclic alkanes
Gauche conformations are generally higher in energy than anti conformations
Which of the following is NOT a Lewis acid
HBr4
Identify the conjugate base HCO2H + -NH2 --- HCO2- + NH3
HCO2-
Symbol for helium
He
Select the polar aprotic solvents
I, II, IV
Select the best leaving group
I-
Select the order of the leaving group ability, putting the best first
I- > Br- > Cl- > H2O
arrange the following butane conformations in the order of increasing energy (lowest to highest)
I<III<II<IV
which of the compounds are chiral
II and III
in the reaction of Cl2 with ethane and UV light, which of the following reactions would be a chain propagation event
II and IV
Which of the following is a tertiary alkyl halide
II, with F
in the reaction of Cl2 with ethane and UV light, which of the following reactions would be a chain termination event(s)
III
which of the following compounds has the lowest heat of combustion (most stable)
III
which of the following structures of 2,3-dimethylbutane is the highest energy conformer
III, all elements are near each other
Which of the following contains the secondary radical carbons
IV and II
Arrange the following butane conformations in the order of decreasing energy (highest to lowest)
IV<II<III<I
What is the Keq for the following equilibrium (pKa of amides 15 and amines 35)
K>1
The symbol for nitrogen is
N
Identify the trans stereoisomer from the following structures
NH2 dashed, NH2 wedge on same side
In the following reaction, identify the conjugate base NH3 + H- --- NH2- + H2
NH2-
which of the following compounds is the strongest base
NH2-
Name the alkane CH3CH2CH2CH2CH2CH2CH2CH2CH3
Nonane
Symbol for Oxygen
O
Which of the following compounds is a Lewis base
OH-
the following alkyl halide is best described as (Has I at the bottom)
Secondary
What is the hybridization of the positively charged carbon in (CH3)3C+
Sp2
What is the hybridization of the negatively charged carbon in (CH3)3C-
Sp3
in the reaction of Cl2 with ethane and UV light which of the following reactions would be a chain initiation event
V
provide an acceptable name for the following compound
bicycle[2.1.1]hexane
Which of the following compounds is a fused bicycle
bicycle[3.2.0]heptane
Highest melting point
big + sign
how do alkyl substituents stabilize a carbocationic center to which they are attached
both a and c
going from left to right in the periodic table, basicity ____ and nucleoephility ____
decreases and decreases
going from left to right in the periodic table, nucleophilicity _____ and leaving group ability ______
decreases and increases
How are the two compounds related (one OH on dashed, one OH on wedge)
diasteromers
select the change in the rate of formation of the product if the concentration of the iodide ion is increased by 4 and the alkyl chloride is halved
doubles
Indicate the statement that is true about enantiomers
enantiomers are mirror image molecules that are not superimposable
select the charge in the rate of formation of the product if the concentration of the iodide ion is increased by 8 and the alkyl chloride is halved
increase by a factor of 4
Identify the NUCELOPHILIC atom in the following reaction
nitrogen
which of the following compounds has only primary and secondary hydrogen atoms
pentane
select the charge in the rate of formation of the product if the concentration of the iodide ion is halved and the alkyl chloride is doubled
remains unchanged
the following alkyl hailed is best described as (Cl equatorial and CH3 axial)
tertiary
Which of the statements below correctly describes the chair conformations of trans-1-ethyl-4-methylcyclohexane
the lower energy chair conformation has both substituents equatorial
how do alkyl substituents destabilize a carbanionic center to which they are attached
through inductive donation of electron density to the carbanionic center
