Chapter 10
The correlation between a molecule's basicity and its ability to act as a leaving group is
The better a molecule can act as a base, the less it can act as a leaving group
Rearrangements occur in which type(s) of reaction(s)?
E1 & Sn1
An alcohol undergoes _____ when it is heated with an acid.
Dehydration
Epoxides are more reactive than ethers due to
Ring strain causing a decrease in stability
Explain why CH3+ has a different three dimensional geometry than CH3-
CH3+ is sp2 hybridized with a vacant p-orbital (Trigonal Planar), CH3- has a lone pair and 3 signma bonds and is therefore sp3 hybridized (Tetrahedral)
What functional group cannot undergo substitution or elimination reactions?
Amines
Three ways in which an alcohol can be converted into an alkyl halide without reacting with HX.
PBr3, PCl3, SOCl2
This kind of alcohol is the easiest to dehydrate
Tertiary alcohol
Alcohols can be activated by
protonation
Name the two difference positions that the hydrogens of cyclohexane can be located in its most stable geometrical conformation.
Axial and Equatorial
Dehydration of secondary and tertiary alcohols are what kind(s) of reactions?
E1 Reactions
A tertiary alcohol cannot be converted to a sulfonate ester because they are too sterically hindered (T/F)
False. A tertiary alcohol can form sulfonate esters, but they are too sterically hindered to undergo a subsequent nucleophilic substitution reaction.
In order to force a secondary alcohol to dehydrate via an E2 mechanism, ____ should be added to the solution prior to elimination.
POCl3
A methyl halide reacts with sodium cyanide in the presence of water. The rate of this reaction is dependent upon
Explain why ethanoic acid (CH3COOH) is a much stronger acid than ethanol (CH3CH2OH)
The ethanoic acid anion is stabilized due to resonance. This means the negative charge of the conjugate base can be shared between two oxygens, and therefore, it is less likely to "regrab" the hydrogen.
Explain the significance of the fact that alcohols and ethers are stronger bases than halide ions.
ROH and ROR must be activated before they can undergo a substitution or elimination reaction with RX.
Converting an alcohol to an RX via a sulfonate ester forms a substitution product with a which kind of configuration (compared to the initial ROH)
Opposite configuration of the alcohol. One SN2 reaction occurs.
Chromic acid oxidizes primary alcohols to _____
carboxylic acids
What is the sequence of steps involved in a radical chain reaction?
Initiation, Propagation, Termination
Which of the following are examples of syn addition to an alkene:
Hydrogenation, Hydration, Hydrobromination, Hydroboration
Hydrogenation and Hydroboration
1-bromobutane reacts with the ethoxide ion in DMF. Explain how the rate of the reaction will change if ethanol is used instead of DMF.
2-bromo-2-methylbutane reacts with methanol. Explain what happens to the rate of the reaction if the alkyl halide is changed to 2-chloro-2-methylbutane
The reaction rate will be slower because the chloride ion is a worse leaving group than the bromide ion
Does 3-bromocyclohexene or bromocyclohexane react faster in an E2 reaction?
3-bromocyclohexene forms 1,3-cyclohexadiene whereas bromocyclohexane forms cyclohexene. 3-bromocyclohexene reacts faster because a conjugated double bond is more stable than an isolated double bond.