Comprehensive Organic Chemistry: Suzuki, Aldol, Grignard, Diels-Alder, and Friedel-Crafts Reactions

In Experiment 18, what type of bond is formed in a Suzuki reaction?

sp²-sp² carbon-carbon bond

In Experiment 18, what are the three key steps in the Suzuki mechanism?

Oxidative addition, transmetalation, reductive elimination

In Experiment 18, what happens during oxidative addition?

Pd(0) inserts into C-X bond and becomes Pd(II)

In Experiment 18, what happens during reductive elimination?

New C-C bond forms and Pd returns to Pd(0)

In Experiment 18, what is the role of Pd/C?

Catalyst

In Experiment 18, why is the reaction considered green chemistry?

It uses water as a solvent instead of organic solvents

In Experiment 18, why is HCl added at the end of the reaction?

To protonate the product and cause precipitation

In Experiment 18, why is methanol used in purification?

Product dissolves while Pd/C does not

In Experiment 19, what is an aldol condensation?

Formation of a β-hydroxy carbonyl followed by dehydration to an α,β-unsaturated carbonyl

In Experiment 19, what forms the enolate?

Base (NaOH)

In Experiment 19, why does dehydration occur easily?

Product is stabilized by conjugation

In Experiment 19, why does acetone react with benzaldehyde instead of itself?

Benzaldehyde is more electrophilic

In Experiment 19, what is the final product?

Dibenzylideneacetone

In Experiment 19, what is lost during condensation?

Water

In Experiment 19, what do coupling constants of 12-18 Hz indicate?

Trans double bond

In Experiment 19, what do coupling constants of 6-12 Hz indicate?

Cis double bond

In Experiment 19, what do coupling constants of 0-3 Hz indicate?

Geminal hydrogens

In Experiment 13, what is a Grignard reagent?

R-MgX (carbon nucleophile)

In Experiment 13, why must the reaction be kept dry?

Water destroys the Grignard reagent

In Experiment 13, what type of reaction occurs with carbonyls?

Nucleophilic addition

In Experiment 13, what is formed when a Grignard reacts with an aldehyde?

Secondary alcohol

In Experiment 13, what is formed when a Grignard reacts with a ketone?

Tertiary alcohol

In Experiment 13, why is magnesium scratched?

To remove oxide layer and increase reactivity

In Experiment 13, why is ether used?

To stabilize the Grignard reagent

In Experiment 14, what reagent generates DMDO?

Oxone and acetone

In Experiment 14, what is DMDO used for?

Epoxidation of alkenes

In Experiment 14, why is the exo product favored?

Less steric hindrance

In Experiment 14, what determines stereoselectivity?

Steric effects

In Experiment 14, why should sodium sulfate be washed with ether?

Product may be trapped in drying agent

In Experiment 15, what type of reaction is the Diels-Alder reaction?

[4+2] cycloaddition

In Experiment 15, what is unusual about this reaction?

It occurs without solvent at room temperature

In Experiment 15, what reaction follows the Diels-Alder step?

Intramolecular nucleophilic acyl substitution

In Experiment 15, what happens if reactants are not in a 1:1 ratio?

Extra starting material appears in NMR

In Experiment 15, what does bubbling with NaHCO₃ indicate?

Presence of a carboxylic acid

In Experiment 17, what type of reaction is Friedel-Crafts alkylation?

Electrophilic aromatic substitution

In Experiment 17, what generates the electrophile?

AlCl₃ and alkyl halide form a carbocation

In Experiment 17, why are two products formed?

Carbocation rearrangement

In Experiment 17, what analytical technique is used?

Gas chromatography (GC)

In Experiment 17, what does GC peak area represent?

Relative composition of compounds

In Experiment 12, what reagent is used to reduce camphor?

NaBH₄

In Experiment 12, what is transferred during the reaction?

Hydride ion (H⁻)

In Experiment 12, why is the exo product favored?

Less steric hindrance

In Experiment 12, what does specific rotation measure?

Composition of stereoisomers

In Experiment 12, what is the formula for specific rotation?

[α] = αobs / (l × c)

In Experiment 12, what does a negative rotation indicate?

Higher amount of isoborneol