Term
Reaction of a terminal alkyne with 2 equivalents of HCl
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Definition
forms a geminal dichloride with the two chlorine atoms on the second carbon, i.e.
R-C(Cl)2CH3 |
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Term
| Deprotonation of a terminal alkyne occurs with ______ and forms an ________ |
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Definition
a strong base such as NaH or NaNH2
an acetylide anion, which is an excellent nucleophile |
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Term
| Hydration of a terminal alkyne with H2SO4/HgSO4 |
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Definition
| gives an aldehyde because it forms an enol RCH=CH(OH) that tautomerizes to the more stable keto form |
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Term
| Hydration of an internal alkyne with H2SO4/HgSO4 gives |
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Definition
| a ketone since it initially forms an enol (RCH=CR(OH)) which tautomerizes to the more stable keto form. |
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Term
| Markovnikov addition of HBr to an unsymmetrical alkane |
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Definition
| results in the bromine added to the more substituted carbon atom because the most stable carbocation is an intermediate. |
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Term
| Markovnikov addition of water to an unsymmetrical alkene (hydration) |
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Definition
| results in the formation of an alcohol, with the OH group going on the most substituted carbon atom due to the formation of the most stable carbocation. |
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Term
| Anti-Markovnikov hydration of an unsymmetrical alkene with BH3 followed by H2O2/OH- |
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Definition
| forms an alcohol where the OH group is on the less substituted carbon. This does not proceed through a carbocation intermediate, but is a result of the syn addition of BH3 to the double bond. Boron goes on the less substituted carbon because of steric effects and is replaced on the same carbon by H2O2/OH- |
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Term
| Addition of the elements of OH and a halide to an alkene (halohydrin formation) occurs when an alkene is contacted with |
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Definition
| a halogen (Br2 or Cl2) and water. Anti addition occurs because the water does a backside attack on the halonium ion intermediate. |
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Term
| Halogenation of an alkene occurs via _____ addition because __________ |
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Definition
| anti addition because of the formation of the intermediate halonium ion intermediate. Backside attack occurs because of steric effects. |
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Term
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Definition
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Term
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Definition
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Term
[image]
What is type of reaction is this? |
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Definition
| Bromination; note anti-addition (trans) |
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Term
| Draw the halohydrin reaction product of cyclohexene with bromine and water. |
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Definition
[image]
Trans addition because of intermediate bromonium ion and backside/underneath attack of the nucleophile. |
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Term
| Define constitutional isomers |
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Definition
| have the same molecular formula but differ the way the atoms are connected |
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Term
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Definition
| have the same molecular formula and the same atom-to-atom connections but differ in the way the atoms are oriented in space. |
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Term
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Definition
| are stereoisomers that are non-superimposable mirror images |
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Term
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Definition
occur when you have two or more stereocenters. One of the pairs of stereocenters has the same configuration and the other pair has the opposite.
RR and RS
If you had RR and SS, they would be enantiomers |
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Term
What is the relationship of the molecules?
[image] |
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Definition
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Term
What is the realtionship of the molecules?
[image] |
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Definition
| They are stereoisomers; specifically diastereomers - one of the stereogenic centers is the same and one is different |
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Term
What is the relationship of these molecules?
[image] |
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Definition
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Term
What is the configuration (R vs S) of the stereoisomers?
[image] |
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Definition
[image]
The top one is R, the bottom is S |
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Term
What is the stereochemical configuration (R or S) of this molecule?
[image] |
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Definition
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Term
Which of the following molecules will not have a dipole moment?
H2O
NH3
CH3CH3
CHCl3 |
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Definition
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Term
Which of the following molecules has a dipole moment?
CH4
CCl4
CH2Cl2
Cl2C=CCl2 |
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Definition
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Term
What is the molecular geometry of formaldehyde?
CH2O |
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Definition
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Term
What is the hybridization of the carbon in formaldehyde?
[image] |
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Definition
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Term
Name the functional groups:
[image] |
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Definition
[image]
alcohol aldehyde ketone carboxylic acid
Remember "R" is any carbon group |
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Term
Specify the type of alcohol (primary, secondary, etc):
[image] |
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Definition
[image]
primary tertiary secondary primary |
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Term
What functional group is present in coniine?
[image]
A. amide B. imine C. amine D. nitrile |
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Definition
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Term
Which of the following is classified as a protic solvent?
A. ethanol
B. ethyl ether
C. Dichloromethane
D. DMSO |
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Definition
Protic solvents have OH groups. The only one in the list is A. Ethanol (CH3CH2OH)
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Term
Which of the following is a polar aprotic solvent:
A. water
B. benzene
C. acetone
D. methanol |
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Definition
Polar aprotic solvents have polar bonds but no OH groups.
The only polar aprotic solvent in the list is C. acetone.
Note: benzene is an aprotic solvent but it is not polar |
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Term
Classify the following reaction as an addition, substitution, elimination or acid-base reaction:
[image] |
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Definition
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Term
Classify the following reaction as an addition, substitution, elimination or acid-base reaction:
[image] |
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Definition
| Addition reaction - water is added across the triple bond to form the enol which rearranges to the more stable keto form. |
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Term
What is/are the enol form/s of the ketone?
[image] |
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Definition
| A and D are the enol forms of the ketone |
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Term
Which of the following cations is the most stable?
[image] |
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Definition
| B. is the most stable (tertiary cation) |
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Term
Which of the following cations is least stable?
[image] |
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Definition
| A is least stable (primary cation). |
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Term
Which of the following cations has unusual stability due to resonance?
[image] |
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Definition
D. has resonance stabilitzation which makes it more stable than a primary cation.
[image] |
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Term
If the energy level of the products is greater than that of the reagents, the reaction is
A. exothermic
B. endothermic |
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Definition
B. endothermic
Energy must be added to the reaction |
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Term
If the energy level of the products is less than that of the reactants, the reaction is said to be
A. Exothermic
B. Endothermic |
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Definition
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Term
If a reaction such as the one below gives products that have undergone skeletal rearrangements, what can you conclude about the most likely mechanism of the reaction?
[image] |
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Definition
| That an intermediate carbocation has formed and undergone rearrangement to form a more stable carbocation (2o to 3o) |
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Term
Which of the following is the best nucleophile?
[image]
A. B. C. |
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Definition
B. because is has a negative charge (vs A) and it is not stabilized by resonance (vs C). |
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Term
| True/False: An alcohol must be transformed into a good leaving group prior to undergoing substitution or elimination reactions. |
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Definition
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Term
What reagent is needed for the following reaction?
[image] |
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Definition
| Anti-Markovnikov addition of water to a double bond is a result of treatment with borane (BH3) followed by alkaline hydrogen peroxide (H2O2/OH-). |
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Term
What reagent is needed for the following reaction?
[image]
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Definition
| Markovnikov addition of water to an alkene can be affected by aqueous sulfuric acid (H2O/H2SO4) |
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Term
Which reagent would affect the following transformation?
[image]
A. CH3OH/H2SO4
B. CH3O-Na+/THF |
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Definition
A. CH3OH/H2SO4
In order for the nucleophile to end up on the most substituted carbon, you need conditions that favor the formation of a carbocation, like SN1-type conditions. The oxygen atom is protonated and that facilitates opening of the epoxide ring on the side that will result in the most stable carbocation (most substituted carbon). |
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Term
Which reagent would affect the following transformation?
[image]
A. CH3OH/H2SO4
B. CH3O-Na+/THF |
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Definition
B. CH3O-Na+/THF
In order for the nucleophile to end up on the least substituted carbon of the epoxide, you need to have SN2-like conditions; a strong nucleophile that is influenced by steric effects and will attack the least-substituted carbon. |
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Term
Determine the product:
[image] |
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Definition
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Term
Determine the product:
[image] |
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Definition
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Term
The pKa of benzoic acid is 4.2 and the pKa of methanol is 15.5. Consider the following equilibrium. Which would be favored, the products or the reactants?
[image] |
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Definition
| The equibrium favors the formation of the reactants. The stronger acid (benzoic acid, pKa 4.2) has the weaker conjugate base. It is not strong enough to remove a proton from methanol. In other words, acid-base equilibria favor the formation of the weaker of the two acids (higher pKa). |
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Term
Name the three functional groups in the molecule:
[image] |
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Definition
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Term
Name the four functional groups in the molecule:
[image] |
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Definition
| ester, thiol, amine, benzene ring |
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Term
Which is the most stable rotational conformation of 1,2-dichloroethane?
[image] |
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Definition
B. The chlorines are farthest apart (staggered, anti)
Note that structure C is the wrong molecule; it is 1,1-dichloroethane. |
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Term
Which is the least stable rotational conformation of 1,2-dichloroethane?
[image] |
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Definition
| D is the least stable; the chlorine atoms are virtually on top of each other, and the conformation is eclipsed. |
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Term
Which is the more stable conformation of methyl cyclohexane?
[image] |
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Definition
| The equatorial isomer (on the left) is more stable; the axial conformation has more crowding due to the other axial hydrogens. |
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Term
A substituted bromo cyclohexane is subjected to potassium t-butoxide and the following three products are found. No rearrangements have occured. What is the starting material?
[image] |
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Definition
[image]
Note that there are three different beta protons on this structure; elimination leads to three different products. |
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Term
A subsituted bromocyclohexane is subjected to elimination conditions (potassium t-butoxide) and gives three products. Which is the major product formed?
[image]
A. B. C. |
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Definition
| Product A is formed the most; the alkene is more highly substutitued; Zaitsev's rule. |
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Term
A primary alkyl halide reacts with a strong nucleophile. What is the most likely mechanism?
SN1 SN2 E1 E2 |
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Definition
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Term
| A tertiary alkyl halide reacts with a strong, bulky base in a polar aprotic solvent. What would be the result and the likely mechanism? |
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Definition
| An elimination reaction would occur since a strong base or nucleophile favors an SN2 or E2 reaction. A tertiary alkyl halide is too sterically hindered to undergo an SN2 reaction, so only E2 elimination occurs. |
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Term
| A primary alkyl halide is contacted with a strong, sterically hindered base. What is the most likely result? |
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Definition
| Elimination reaction via an E2 mechanism since a strong sterically hindered base is a lousy nucleophile. |
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Term
| A secondary alkyl halide is reacted with a weak nucleophile/weak base. What is the likely result? |
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Definition
| A mixture of SN1 and E1 products. |
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Term
| A secondary alkyl halide reacts with a strong base such as CH3CH2O-. What is the likely result? |
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Definition
| A mixture of SN2 and E2 products since a strong base is also a strong nucleophile. |
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Term
| What is the result if a stereogenic center (chiral carbon) is subjected to SN2 reaction conditions? |
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Definition
| Inversion of the stereocenter will occur. |
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Term
| What is the result if a stereocenter is subjected to SN1 reaction conditions? |
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Definition
| Racemization of the stereocenter will occur. |
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Term
| Which reaction mechanism, SN1 or SN2 would exhibit second order kinetics? |
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Definition
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Term
Which reaction mechanism, E1 or E2, would exhibit first order reaction kinetics?
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Definition
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Term
| Which reaction mechanism, SN1 or SN2, is favored by polar, protic solvents? |
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Definition
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Term
| Which reaction mechanism, E1 or E2, is favored by polar aprotic solvents? |
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Definition
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Term
What is the product of the following reaction:
[image] |
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Definition
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Term
What is the name of the following reaction?
[image] |
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Definition
| The Williamson ether synthesis. |
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Term
| What reagent would be used to convert a primary alcohol to an alkyl chloride? |
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Definition
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Term
| What reagent could be used to convert a primary or secondary alcohol to an alkyl bromide? |
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Definition
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Term
What reaction conditions would work the best for the transformation of 2-bromopentane to 1-pentene?
A. KOC(CH3)3/ HOC(CH3)3
B. NaOH/H2O
C. Na/NH3
D. H2/Pd/C
E. None of the above |
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Definition
A. KOC(CH3)3/ HOC(CH3)3
A strong, bulky non-nucleophilic base is best for elimination reactions. |
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Term
What is the stereochemical configuration (R vs S) of this molecule?
[image] |
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Definition
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Term
Order the following substituents according to the Cahn-Ingold-Prelog priority system
A. Cl
B. Br
C. CH3
D. CH2OH
E. CO2H |
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Definition
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Term
Name the alkene, including E/Z
[image] |
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Definition
| (3E) 4-ethyl-3-methyl-3-heptene |
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Term
Name the alkene, including E/Z
[image] |
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Definition
| (4Z) 4,5-diethyl-4-octene |
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Term
| What is the result if an alkyne is reacted with two equivalents of strong acid (i.e. HBr)? |
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Definition
[image]
Two equivalents of acid are added in a Markovnikov fashion to give a geminal halide |
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Term
| How can you produce a cis-alkene from an alkyne? |
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Definition
Use Lindlar's catalyst
[image] |
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Term
What is the result if you react an alkyne with sodium in liquid ammonia?
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Definition
[image]
You get a trans- alkene |
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Term
What is the product of the following reaction?
[image] |
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Definition
[image]
Reduction of an alkyne with hydrogen and a metal catalyst takes the triple bond all the way down to the alkane. It goes through the cis double bond but doesn't stop. |
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Term
Which is the product of hydrogenation of this double bond?
[image] |
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Definition
[image]
Hydrogenation is always syn addition, so this product has to have both methyl groups "cis". |
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Term
What reagent is needed to affect the following transformation?
[image] |
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Definition
LiAlH4 or NaBH4
will add hydride (H-) in an SN2 reaction - hydride is the nucleophile and replaces the halide just like other nuclophiles.
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Term
What is the product of the following reaction?
[image] |
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Definition
[image]
LiAlH4 adds Hydride (H-) as a nucleophile to the epoxide on the least substituted carbon. |
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