Organic Chemistry Exam Review: Chapters 9-12

Vocabulary practice flashcards covering functional groups, reagents, reaction mechanisms, and nomenclature from organic chemistry chapters 9 through 12.

9-BBN

A reagent used in the hydroboration-oxidation of alkynes, followed by $H_2O_2$ and $NaOH$, to yield an aldehyde final product.

Lindlar's catalyst

A poisoned catalyst used with $H_2$ to reduce an alkyne specifically to a cis-alkene.

Vicinal dihalide

A dihalide in which the halogens are attached on adjacent carbons.

Geminal dihalide

A dihalide in which both halogen atoms are attached to the same carbon atom.

Homolytic cleavage

A bond-breaking process where movement of individual electrons, shown using fishhook arrows, produces two equal halves that each have an unpaired electron.

Propagation step

A step in a radical reaction, such as monochlorination, where a radical reacts with a stable molecule to generate a product and a new radical.

Disiamylborane

A hindered borane reagent used in the conversion of terminal alkynes to aldehydes through hydroboration-oxidation.

Alkynide ion

A reactive intermediate formed when a strong base such as sodium amide ($NaNH_2$) deprotonates a terminal alkyne.

NBS (N-Bromosuccinimide)

A reagent used to achieve allylic bromination under free radical conditions, often involving light ($hv$).

Thermal cracking

A process, such as the heat-induced breakdown of butane, that produces ethyl radicals via homolytic cleavage.

Sodium amide ($NaNH_2$)

A strong base typically dissolved in liquid ammonia ($NH_3$) to prepare terminal alkynes by deprotonating them to drive formation of the alkynide ion.

Acid-catalyzed hydration

A reaction that adds water across a triple bond; for internal symmetrical alkynes like 3-hexyne, it yields a single ketone product.

MCPBA

A peroxyacid reagent used in the synthesis of epoxides from alkenes.

Allylic position

The carbon atom adjacent to a carbon-carbon double bond, which contains the weakest $C-H$ bonds in certain structures.

Regioisomeric compounds

Different constitutional isomers formed when a reaction, such as allylic bromination of methylenecyclopentane, can occur at multiple distinct sites.