CHEM Chapter 9: Ethers and Epoxides

What is the structure of an ether?

Oxygen atom bonded to two carbon groups (R-O-R'), with sp³ hybridized oxygen.

How are ethers named in the common system?

List alkyl (or aryl) groups alphabetically + "ether."

How are ethers named in IUPAC?

Name smaller group + oxygen as an 'alkoxy' substituent on the parent alkane.

Why do ethers have lower boiling points than alcohols?

No hydrogen bonding between ether molecules.

Why are ethers good solvents for Grignard reagents?

Ethers are aprotic (no H to react with carbanions) and polar.

What is Williamson Ether Synthesis?

An SN2 reaction where an alkoxide ion attacks an alkyl halide to form an ether.

Why can't tertiary alkyl halides be used in Williamson synthesis?

They undergo elimination (E2) instead of substitution (SN2).

What is an epoxide?

A three-membered cyclic ether; very strained and reactive.

How are epoxides made in the lab?

Oxidation of alkenes using peroxycarboxylic acids (e.g., mCPBA).

How do epoxides react under acidic conditions?

Protonate oxygen -> water or other nucleophile attacks -> ring opens.

Where does a nucleophile attack in a simple epoxide?

At the less hindered (less substituted) carbon atom

What are crown ethers?

Large cyclic ethers that bind metal ions inside their cavity.

How are crown ethers named?

'Number of atoms' - 'crown' - 'number of oxygens' (e.g., 18-crown-6).