OrgoChem II

Ethers and Epoxides

Williamson ether synthesis and epoxide openings

Summary

Master Williamson and epoxide regioselectivity under basic vs acidic conditions. Full reference is on the external link.

What you need to know:

This topic covers ethers and epoxides. Focus on mastering the key concepts in the "Must know checklist" below. Follow the study steps systematically, and use practice problems to reinforce your understanding. The external reference provides comprehensive coverage of all concepts.

Video Tutorial

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Ether and Epoxide Reactions

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Must know checklist

0 / 5 complete

Williamson ether synthesisalkoxide (RO-) + alkyl halide → ether via SN2; primary halide works best; intramolecular forms epoxides
Ether and Epoxide Reactions→
Epoxide openingbasic conditions (RO-, OH-) attack less substituted C (SN2); acidic conditions (H+) attack more substituted C (protonated epoxide); both give anti addition
Williamson Ether Synthesis - SN2 Mechanism→
Stereochemistryepoxide opening is always anti (trans-diaxial); nucleophile and leaving group end up trans to each other
Epoxide Opening - Acidic vs Basic Conditions→
Ether cleavagestrong acids (HI, HBr) cleave ethers; mechanism depends on substitution; can give alkyl halides or alcohols
Epoxide Stereochemistry - Anti Addition→
Ethers as protecting groupsprotect alcohols from oxidation/reduction; remove with strong acid (HBr, HI); useful in synthesis planning
Ether Cleavage Reactions→

Common mistakes

Attacking wrong carbon in epoxide (basic: less substituted; acidic: more substituted)

Forgetting anti addition in epoxide opening

Using secondary halide in Williamson (favors E2 over SN2)