Alcohols & Phenols Flashcards
Alcohols
Are compounds that possess a hydroxyl group (OH) & are characterized by names ending in “ol”
Nomenclature of alcohols
- Use the same 4 steps to name it as alkanes except it ends in “ol”
- Have to name it in a way that the longest chain contains the carbon atom that is directly connected to the OH
- The OH gets the higher priority over double bonds & other substituents groups
Phenol
Is a hydroxyl group attached to a phenyl
_______ is the parent’s name when a substituent is attached to it
Phenol
Alcohols have higher boiling points because of the __________
Hydrogen bonds
What are the two regions that alcohols have?
- Hydrophobic region
- Hydrophilic region
Hydrophobic region
Region that doesn’t interact with water
Hydrophilic region
Region that does interact with water through hydrogen bonds
Methanol is ________ in water but butanol is soluble
Miscible
Miscible
Can be mixed in a solvent in any proportion
Soluble
Means that only a certain volume of solute will dissolve in specified amount of solvent at room temp
As the size of the hydrophobic region increases __________ in water decreases
Solubility
Alcohols with more than eight carbons (like nonanol & decanol) are considered to be ________ in water
Insoluble
The conjugated base of alcohols are called what?
Alkoxide ion
pKa for most alcohols is between what?
15-18
What are the two common ways to deprotonate an alcohol to form an alkoxide ion?
- A strong base like sodium hydride because H- deprotonates the alcohol to generate H2
- Using Li, Na, or K to react with the alcohol to liberate H2
What are the factors affecting the acidity of alcohols & phenols?
- Resonance
- Induction
- Solvation effect
Resonance
If a compound has resonance its more acidic
When phenol is deprotonated, the conjugated base is stabilized by ______ so it’s pretty acidic
Resonance
Induction
Alcohols that have induction are more acidic by the electron withdrawing affect
Solvation effect
Straight chain alcohol more acidic than branched alcohols due to steric affect
Alcohols can be prepared by substitution reaction where a leaving group is replaced by __________
Hydroxyl group
_________, _________, & __________ adds an OH in an addition reaction
Acid catalyzed hydration, oxymercuration demurcuration & hydroboration
Converting ketone (or aldehyde) to an alcohol is a __________
Reduction (requires a reducing agent)
What are the 3 reducing reagents?
- H2/Pt, Pd, or Ni
- Sodium borohydride (NaBH4) & solvent EtOH, MeOH, or H2O
- Lithium aluminum hydride (LAH or LiAlH4) & H2O
Describe the mechanism of a reduction of a ketone or aldehyde with NaBH
- Nucleophilic attack
- Proton transfer
Describe the mechanism of a reduction of a ketone or aldehyde with LAH
- Nucleophilic attack
- Proton transfer
______ & ______ is better than hydrogenation because they can selectively reduce a carbonyl group
NaBH4 & LAH
____ is more reactive so ______ is less selective & will react with carboxylic acid or an ester to produce an alcohol
LAH (NaBH4 wont)
Describe the mechanism of a reduction of an ester with LAH
- Nucleophilic attack
- Loss of leaving group
- Nucleophilic attack
- Proton transfer
Diols
Compounds with two hydroxyl groups
How do you name diols?
- The position of both hydroxyl groups are identified with the numbers of places before the parent
- The suffix “diol” added at the end
Diols can be made from ______ via reducing agents
Diketones
Diols can also be made by __________ of an alkene
Dihydroxylation (Ani or Syn)
Grignard Reagent
Formed by the reaction between an alkyl halide & magnesium
Carbon is more electronegative than _____ where their bond can be seen as ionic bond
Mg
Grignard reagents are carbon _______ that can attack carbonyl group of ketones & aldehydes
Nucleophiles
Describe the mechanism of Grignard reagent with a ketone or aldehyde
- Nucleophilic attack
- Proton transfer
- Product is an alcohol
Grignard reagents also react with esters to make alcohols by adding two _____ groups
R (alkyl groups)
Describe the mechanism of a Grignard reagent with an ester
- Nucleophilic attack
- Loss of leaving group
- Nucleophilic attack
- Proton transfer
Its not possible to make a Grignard reagent without _______
Protecting
What are the 3 steps in protecting to make a Grignard reagent?
- Protect the hydroxyl group by removing & converting the hydroxyl group into a new group called a protecting group
- Form the Grignard reagent & perform the desired Grignard reaction
- Deprotect by converting the protecting group back into a hydroxyl group
__________ is a protecting group
Trimethylsilyl ether (OTMS)
Trimethylsilyl is formed by the reaction between an ______ & ________
Alcohol & Trimethylsilyl chloride (TMSCl)
After Grignard reaction is made the ________ group is removed easily with either H3O+ or fluoride ion such as tetrabutylammonium fluoride (TBAF)
Trimethylsilyl
_________ are prepared industrially via multistep process involving the formation & oxidation of cumene
Phenols
To replace an OH with Cl have to use what?
ZnCl2 (As a catalyst) (It makes the OH a better leaving group)
_________ alcohols will react in an SN2 reaction
Primary alcohol
Primary & Secondary alcohol will react with _____ or ______ via SN2 reaction
SOCl2 or PBr3
In an E1 an OH can be protonated but in an E2 it can be turn into _______ followed by a strong base
OTs
Primary alcohol has two protons at the alpha position (carbon with the OH) so therefore can be oxidized twice where the 1st oxidation produces ______ & 2nd oxidization produces ________
Aldehyde, Carboxylic Acid
Secondary alcohol only has one proton at the alpha position so they can only be oxidized once forming a _________
Ketone
________ alcohol don’t have any protons so can’t be oxidized
Tertiary
_________ is the most common oxidizing reagent where it is formed from sodium dichromate (Na2Cr2O7) or chromium trioxide (CrO3) in an aqueous acidic solution
Chromatic Acid H2CrO4
When a primary alcohol is oxidized with chromic acid a __________ is obtained
Carboxylic Acid
When pyridinium chlorochromate (PCC) is used as oxidizing reagent an ________ is the final product
Aldehyde
______ is formed from the reaction between pyridine, chromium trioxide & hydrochloric acid
PCC
__________ is the solvent used with PCC
Methylene Chloride (CH2Cl2)
Phenol undergo oxidization to produce __________
Benzoquinone
_________ such as benzoquinone can be converted to hydroquinones
Quinones
The ___________ rearrangement is a {3,3] sigmatropic rearrangement and is commonly observed for allylic vinylic ethers
Claisen rearrangement
The Claisen rearrangement is also observed for _____________ ethers
Allylic aryl ethers
During a Claisen rearrangement with aryl group (phenyl) & allylic group it is turned into a ketone and then tautomerized into an _________
Alcohol
The reaction favors the tautomerization into the alcohol because it reforms the ___________ of the compound
Aromaticy