Epoxides - PROF. R. JAGESSAR LECTURE NOTES

This set of vocabulary flashcards covers the definition, nomenclature, synthesis methods (including peroxyacids and halohydrin cyclization), and reactions of epoxides (oxiranes) and other cyclic ethers like oxetanes, furans, and pyrans.

Epoxides

Three-membered cyclic ethers, also referred to as oxiranes, that serve as valuable synthetic intermediates for converting alkenes to various functional groups.

Peroxyacid ($RCOOOH$)

A carboxylic acid containing an extra oxygen atom in a $-O-O-$ (peroxy) linkage, used to convert an alkene into an epoxide.

Epoxide Common Nomenclature

A naming system formed by adding the word "oxide" to the name of the alkene that underwent oxidation.

Oxirane (Systematic Nomenclature)

A systematic nomenclature system where epoxides are named as derivatives of ethylene oxide (oxirane); ring atoms are numbered starting at the heteroatom and moving to provide the lowest substituent numbers.

MCPBA

Meta-chloroperoxybenzoic acid (meta-carbon substituted with chlorine), a specific peroxyacid used in $CH_2Cl_2$ to synthesize epoxides from alkenes.

Halohydrin

A molecule featuring a halogen atom bonded to the $\beta$-carbon relative to a carbon bearing an $-OH$ group.

Base Promoted Cyclization

A variation of the Williamson-Ether synthesis where a base reacts with a halohydrin to form an alkoxide, which then undergoes an intramolecular $S_N2$ attack on the carbon bearing the halogen leaving group to form an epoxide.

Bromonium ion

The intermediate formed during the synthesis of a halohydrin from the reaction of an alkene with a halogen (such as $Br_2$) in the presence of water.

Oxetane

A four-membered cyclic ether.

Furan (Oxolane)

A five-membered cyclic ether.

Pyran (Oxane)

A six-membered cyclic ether.

Dioxane

A cyclic ether containing two oxygen atoms, such as $1,4$-dioxane or $4$-methyl-$1,3$-dioxane.

Grignard Reaction with Epoxides

A reaction where an epoxide reacts with a Grignard reagent to produce an alcohol that contains two more carbons than the parent Grignard molecule.