Unit 11: Alcohols, Ethers, and Epoxides
The hydroxyl group playing both roles at once, oxygen bridging two carbons, and the strained three-membered ring that answers to acid and base differently.
7 topics · 23 questions
Each topic is a path, not a menu: work down it in order and every question builds on the one above. Click any of them to watch the answer draw itself.
Nomenclature and Properties of Alcohols
- How it worksHow does an alcohol's hydroxyl group hydrogen bond to water molecules to pull the whole molecule into solution?
- Worked exampleFind the correct IUPAC name for the six-carbon alcohol with a hydroxyl on carbon 2 and a methyl on carbon 4.
- Going furtherWhat happens to an alcohol's boiling point as its carbon chain grows and the hydroxyl's share of the molecule shrinks?
Your turn1 of 2
What is the correct IUPAC name for the six-carbon alcohol with a hydroxyl on carbon 2 and a methyl on carbon 4?Alcohols as Nucleophiles and as Electrophiles
- How it worksHow does protonating an alcohol's oxygen turn a poor leaving group, hydroxide, into a good one, water?
- Worked exampleFind the product when tert-butanol is treated with concentrated HBr, turning the hydroxyl into a leaving group first.
- Common mistakeWhy can't an alcohol undergo SN2 substitution directly with hydroxide itself acting as the leaving group?
- Going furtherWhat happens to an alcohol's reactivity once its hydroxyl is converted into a tosylate instead of being protonated?
Your turn1 of 2
Tert-butanol is treated with concentrated HBr. What is the product?Oxidation of Alcohols to Aldehydes, Ketones, and Acids
- How it worksHow does a chromium oxidant pull a hydride off the carbon bearing the hydroxyl group to form a new carbonyl?
- Worked exampleFind the oxidation product when 2-pentanol is treated with PCC versus when 1-pentanol is treated with PCC.
- Common mistakeWhy doesn't a tertiary alcohol undergo this same kind of oxidation at all?
- Going furtherWhat happens to a primary alcohol's oxidation product when Jones reagent is used in place of the milder PCC?
Your turn1 of 2
2-pentanol is treated with PCC, and separately 1-pentanol is treated with PCC. What are the two oxidation products?Williamson Ether Synthesis
- How it worksHow does an alkoxide's oxygen attack an alkyl halide in a clean SN2 reaction to form the new ether bond?
- Worked exampleFind the product when sodium ethoxide reacts with bromomethane in a Williamson ether synthesis.
- Common mistakeWhy does the Williamson synthesis fail so badly when the alkyl halide chosen is tertiary instead of primary?
Your turn1 of 2
Sodium ethoxide reacts with bromomethane in a Williamson ether synthesis. What is the product?Acid-Catalyzed Ring Opening of Epoxides
- How it worksHow does protonating the epoxide oxygen build up enough positive character at the more substituted carbon for attack there?
- Worked exampleFind the product when 2,2-dimethyloxirane is opened by methanol under acidic conditions.
- Going furtherWhat happens to the stereochemistry at the attacked carbon: does ring opening give inversion or retention there?
Your turn1 of 2
2,2-dimethyloxirane is opened by methanol under acidic conditions. At which carbon of the epoxide does methanol's oxygen end up bonded?Base-Catalyzed Ring Opening of Epoxides
- How it worksHow does a strong nucleophile attack the less hindered carbon of an epoxide directly, in a straightforward SN2 step?
- Worked exampleFind the product when 2,2-dimethyloxirane is opened by sodium methoxide under basic conditions.
- Ties togetherHow does comparing acid-catalyzed and base-catalyzed epoxide opening bring the whole SN1-versus-SN2 logic back?
Your turn1 of 2
2,2-dimethyloxirane is opened by sodium methoxide under basic conditions. At which carbon does methoxide's oxygen end up bonded?Thiols and Sulfides
- How it worksHow do sulfur's larger, more polarizable lone pairs make a thiol a stronger nucleophile than its matching alcohol?
- Worked exampleFind the product when a thiolate ion reacts with bromoethane in an SN2 reaction to form a sulfide.
- Going furtherWhat happens to a sulfide when it gets oxidized further, first to a sulfoxide and then all the way to a sulfone?
Your turn1 of 2
A thiolate ion reacts with bromoethane in an SN2 reaction to form a sulfide. What is the product?