Covers the structure, naming and classification of alcohols and phenols, including IUPAC and common naming systems with examples, and the differences between alcohols, phenols and ethers. It then goes through acid-base behaviour, the chemical reactions of alcohols and phenols, and esterification with its biological roles. A closing section compares the acidity of phenols and alcohols and describes the Reimer–Tiemann and Kolbe reactions, with thiols briefly introduced.
Topic 21 of 42 in the MU Sofia syllabus for Chemistry (Medicine, Year 1). The free AceMed note covers it in 17 sections, about 1,229 words (9 min of reading), with 24 flashcards.
In this note
Alcohols and phenols
Structure and nomenclature.
Homologous series :
Types of alcohols and phenols.
Acid – Base properties (Of Alcohols)
Chemical properties of alcohols.
Esterification
Nucleophilic substitution (SN) –
Reaction with hydrogen bromide.
Oxidation
Reactions of phenols.
Acylation, nitration and bromination.
Some important naturally occurring thiols.
High Yield
Acidity of Phenols vs Alcohols
Reimer–Tiemann Reaction (Phenols)
Kolbe Reaction (Phenols)
Alcohols and phenols
Alcohols, phenols, and ethers are important classes of organic compounds with distinct structural features, properties, and applications.
1. Structural Characteristics:
Alcohols contain a hydroxyl (-OH) group attached to a saturated carbon atom.
Phenols feature a hydroxyl group (-OH) directly bonded to an aromatic ring.
Ethers consist of two alkyl or aryl groups bonded to an oxygen atom.
2. Properties:
Ethers have lower boiling points compared to alcohols due to the absence of hydrogen bonding.
Alcohols and phenols are generally soluble in organic solvents but insoluble in water.
Alcohols exhibit basic properties due to the presence of the hydroxyl group.
Some ethers, like diethyl ether, have narcotic effects and are used as general anaesthetics.
Structure and nomenclature.
1. Alcohols:
Structure:
Contain a hydroxyl group (OH) bonded to a saturated carbon atom.
The carbon atom with the OH group is sp³ hybridized.
They can have one, two, or three OH groups per molecule, classified as monohydric, dihydric, or trihydric alcohols, respectively.
Nomenclature:
IUPAC system:
Identify the longest carbon chain containing the OH group as the parent chain.
Change the "-ane" suffix of the corresponding alkane to "-ol".
Number the carbon chain to give the carbon with the OH group the lowest possible number.
Use numbers to indicate the positions of other substituents.
Example: CH3-CH2-CH2-OH is named butan-1-ol (1 refers to the position of the OH group).
Common system:
Name the alkyl group attached to the OH group and add the word "alcohol".
Example: CH3-CH2-CH2-OH is named propyl alcohol.
2. Phenols:
Structure:
Contain a hydroxyl group (OH) directly bonded to a benzene ring.
The carbon atom attached to the OH group is sp² hybridized.
Can have additional substituents on the benzene ring.
Nomenclature:
IUPAC system:
Use "hydroxy-" as a prefix before the name of the benzene ring (benzene becomes "benzene").
Number the carbon atoms on the ring to give the OH group the lowest possible number (if there are other substituents).
Indicate the positions of other substituents with numbers.
Example: HO-C6H5 is named phenol, and Cl-C6H4-OH (Cl at position 2) is named 2-chlorophenol.
Common system:
Use the term "phenol" and add the names or positions of any substituents on the ring.
Example: Cl-C6H4-OH can also be called chlorophenol.
Continue reading free
The whole note, all 17 sections, is free with an AceMed account, with its 24 flashcards. Premium adds flashcard recall, highlights and Ask AI.
