Explains different methods for synthesizing phenols and ethers, including the Williamson ether synthesis and other laboratory techniques. Discusses reaction conditions and mechanisms.
Phenol (C₆H₅OH) undergoes oxidation in air to form quinones and other colored compounds, which may impart a yellowish or brownish color.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
Methyl magnesium bromide (CH₃MgBr) reacts with propanal (CH₃CH₂CHO), adding the methyl group to the carbonyl, yielding butan-2-ol (CH₃CH(OH)CH₂CH₃) after hydrolysis.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
Propan-2-one (CH₃COCH₃) reacts with CH₃MgBr, adding a methyl group to the carbonyl carbon, yielding 2-methylpropan-2-ol ((CH₃)3COH) after hydrolysis, which is a tertiary alcohol.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
Propan-1-ol (CH₃CH₂CH₂OH) oxidizes to propanal (CH₃CH₂CHO) with PCC, which lacks the CH₃CO- group and does not give an iodoform reaction.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
Ethane-1,2-diol (CH₂OH-CH₂OH), or ethylene glycol, is widely used in antifreeze and hydraulic fluids due to its low freezing point and high boiling point.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
Pentan-2-ol (CH₃CH(OH)CH₂CH₂CH₃), a secondary alcohol, is oxidized to pentan-2-one (CH₃COCH₂CH₂CH₃) with PCC.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
Propan-1-ol (CH₃CH₂CH₂OH), a primary alcohol, is oxidized to propanal (CH₃CH₂CHO) with PCC, which stops at the aldehyde stage.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
Pentan-2-ol (CH₃CH(OH)CH₂CH₂CH₃) oxidizes to pentan-2-one (CH₃COCH₂CH₂CH₃), which has a CH₃CO- group and gives a positive iodoform test.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
PCC oxidizes secondary alcohols to ketones without further oxidation, unlike strong oxidants like KMnO₄.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
Ethanol (CH₃CH₂OH) is commonly used as a fuel additive (e.g., in gasoline) to improve the octane rating and reduce emissions.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
Pentan-3-ol (CH₃CH₂CH(OH)CH₂CH₃), a secondary alcohol, oxidizes to pentan-3-one (CH₃CH₂COCH₂CH₃) with PCC.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
1-Pentene (CH₂=CH-CH₂CH₂CH₃) undergoes hydroboration-oxidation with BH₃ and H₂O₂, adding -OH anti-Markovnikov to form pentan-1-ol (CH₃(CH₂)3CH₂OH).
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
