Organic Oxidations and Reductions

what is oxidation

increasing oxygen content/decreasing the hydrogen content of a compounds

what is reduction

decreasing the oxygen content/increasing hydrogen content of a compound

If a reaction occurs in which there is a net addition or net elimination of hydrogen and oxygen

the reaction is not oxidation or reduction

What are examples of reactions involving hydrogen and oxygen that are not oxidation/reduction reactions

dehydration of alcohol, hydration of alkene

Converting ethanol to ethanal is

oxidation

Converting ethanal to ethanoic acid is

oxidation

Hydrogenation of a double or triple bond is

reduction

What are the most widely used types of oxidation reagents?

chromium (VI) and manganese (VII)

What are the chromium oxidation reagents

CrO₃, K₂Cr₂O₇, K₂CrO₄

what are the manganese oxidation reagents

KMnO₄

Chromium reagents for oxidation are normally used under BLANK conditions, where all are converted into the active oxidant BLANK

acidic, H₂CrO₄

Manganese oxidation reagents are used under BLANK conditions

basic

What happens when chromic acid or hot basic permanganate are used in an oxidation reaction

they do not stop until all hydrogen atoms attached to the carbon atoms undergoing oxidation have been removed

What type of reagents allows oxidation to stop at the aldehyde stage in the oxidation primary alcohols

anhydrous chromium (IV) reagents

What are the anhydrous chromium reagents

chromium trioxide-pyridine complex (CrO₃-2 pyridine), pyridinium chlorochromate (PCC), and pyridinium dichromate (PDC)

chromium anhydrous reagents are all soluble in

organic solvents

Hot chromic acid and hot basic permanganate react with BLANK to give oxidative cleavage products

alkenes, alkynes, and alkylbenzenes

Oxidation begins on the BLANK atom of alkylbenzenes, only when is has one or more BLANK, to produce benzoic acids

benzylic carbon, benzylic hydrogen atoms

Cleavage of vicinal diols happens via

periodic acid (HIO₄)

Cleavage of alkenes happens via

ozone

Cleavage of methyl ketones happens via

alkaline solutions of halogens (haloform reaction)

What reagents react with alkenes and alkynes to give oxidative addition products

Cold alkaline permanganate, osmium tetroxide, peroxy acids

Reductions of carbonyl compounds are usually performed with

complex metal hydrides

Reductions of alkenes are performed with

catalytic hydrogenation

Reductions of alkynes are performed with either

catalytic hydrogenation or alkali metals in ammonia

Identify the mechanism

Clemmensen Reduction

Identify the mechanism

Wolff-Kishner Reduction