PHOrgChem (Lecture) | Module 8 (Part 2: REACTIONS OF ALDEHYDE, and KETONE)

Carbonyl Group

Aldehydes and Ketones are highly reactive compounds due to the presence of the?

Nucleophilic Addition Reactions

The carbonyl group in aldehyde and ketone is electrophilic, making it susceptible to attack by nucleophiles, which are electron-rich species.

Nucleophilic Addition Reactions

EXAMPLE REACTION:
Acetaldehyde (CH₃CHO) + HCN → Cyanohydrin (CH₃CH(OH)CN)

Cyanohydrins

NUCLEOPHILIC ADDITION REACTIONS: The reaction with the hydrocyanic acid leads to the formation of?

Nucleophilic Addition Reactions

The carbon in the carbonyl group (C=O) of aldehyde and ketone is SLIGHTLY POSITIVE; it easily attacks things with extra electrons called NUCLEOPHILES.

Slightly Positive

The carbon in the carbonyl group (C=O) of aldehyde and ketone is _______________; it easily attacks things with extra electrons called NUCLEOPHILES.

Nucleophiles

The carbon in the carbonyl group (C=O) of aldehyde and ketone is SLIGHTLY POSITIVE; it easily attacks things with extra electrons called _________.

Nucleophilic Addition Reactions

EXAMPLE: when hydrocyanic acid reacts with acetaldehyde (a simple aldehyde), the negative charge part of HCN attacks the carbon in carbonyl group, forming new compound called cyanohydrin, which has both an (-OH) and the CN group attached to the carbon.

Nucleophilic Addition Reactions

Basically, the aldehyde grabs onto the part of the HCN and turns into a more complex, stable molecule.

Nucleophilic Addition Reactions

This kind of reaction is really common in organic chemistry and helps build more useful biologically active compounds.

Reduction Reactions

Aldehydes and Ketones can be REDUCED TO ALCOHOLS using reducing agents.

Reduction Reactions

This reaction typically involved ADDITION OF HYDRIDE IONS

Hydride Ions

Reduction Reactions typically involved ADDITION OF?

Reduction Reactions

A process using a special chemical called REDUCING AGENT like SODIUM BOROHYDRIDE that gives extra hydrogen to the molecule

Sodium Borohydride

Reduction Reactions is a process using a special chemical called REDUCING AGENT like _________________ that gives extra hydrogen to the molecule

Reduction Reactions

EXAMPLE REACTION: CH₃CHO + NaBH₄ → CH₃CH₂OH

Reduction Reactions

EXAMPLE: if we take acetaldehyde, a simple aldehyde that reacts with sodium borohydride, it gets reduced to ethanol, which is an alcohol. The hydride ion, the hydrogen with extra electron is added to the carbon in the carbonyl group, charging the double bond to a single bond and adding an (-OH) group

Reduction Reactions

This kind of reaction is important in both lab chemistry and biological systems, where similar reduction happens in the body using natural reducing agents.

Natural Reducing Agents

Reduction Reactions is a kind of reaction is important in both lab chemistry and biological systems, where similar reduction happens in the body using?

Aldol Condensation

An aldehyde or ketone undergoes a reaction with another molecule of the same aldehyde or ketone, forming a beta-hydroxy aldehyde or ketone which can undergo dehydration to form an alpha-beta unsaturated carbonyl carbon

Aldol Condensation

EXAMPLE REACTION:

2 CH₃CHO → CH₃CH(OH)CH=CH₂

CH₃CH(OH)CH=CH₂ → CH₃CH=CHCHO

Aldol Condensation

The reaction between acetaldehyde under basic conditions which forms crotonaldehyde, an alpha-beta unsaturated aldehyde after dehydration.

Crotonaldehyde

ALDOL CONDENSATION: The reaction between acetaldehyde under basic conditions which forms ___________, an alpha-beta unsaturated aldehyde after dehydration.

Alpha-Beta Unsaturated Aldehyde

ALDOL CONDENSATION: The reaction between acetaldehyde under basic conditions which forms crotonaldehyde, an _________________________ after dehydration.

Formation of Acetals and Ketals

Aldehydes and ketones react with alcohols in the presence of acid catalysts to form new compounds, acetals from aldehydes and ketals from ketones.

Acid Catalyst

The __________ helps speed up the Formation of Acetals and Ketals reaction

Formation of Acetals and Ketals

IN SIMPLE TERMS, acetal formation when acetaldehyde reacts with methanol, it forms an acetal, which has two methoxy groups attached to the same carbon.

Methanol

IN SIMPLE TERMS, acetal formation when acetaldehyde reacts with __________, it forms an acetal, which has two methoxy groups attached to the same carbon.

Two Methoxy Groups

IN SIMPLE TERMS, acetal formation when acetaldehyde reacts with methanol, it forms an acetal, which has __________________ attached to the same carbon.

Acetal

IN SIMPLE TERMS, acetal formation when acetaldehyde reacts with methanol, it forms an ______, which has two methoxy groups attached to the same carbon.

Formation of Acetals and Ketals

IN SUMMARY, this process involves aldehydes and ketones reacting with alcohols to form stable acetals or ketals, which are useful in protecting the carbonyl compounds in various reactions

Acetals, and Ketals

Useful in protecting the carbonyl compounds in various reactions

Formation of Acetals and Ketals

EXAMPLE REACTION: CH₃CHO + CH₃OH → CH₃CH(OCH₃)₂ (Acetal formation)

Reactive

FORMATION OF ACETALS AND KETALS (ACETAL/KETAL FORMATION): The carbonyl group from aldehydes and ketones is _________ when an alcohol like methanol is present.

Hemiketal, or hemiacetal intermediate

FORMATION OF ACETALS AND KETALS (ACETAL/KETAL FORMATION): The alcohol oxygen can attack the carbonyl carbon, forming a _________, or ___________

Alcohol group, and ether

FORMATION OF ACETALS AND KETALS (ACETAL/KETAL FORMATION): This step creates a structure with both an _________, and __________ attached to the same carbon.

Acid Catalyst

FORMATION OF ACETALS AND KETALS (ACETAL/KETAL FORMATION): In this formation, in the presence of an _________, the hemiketal or hemiacetal undergoes further reaction.

Dehydration

FORMATION OF ACETALS AND KETALS (ACETAL/KETAL FORMATION): The alcohol molecule loses water, which is a process called _________, and another alcohol molecule adds to the carbonyl group.

Ether

FORMATION OF ACETALS AND KETALS (ACETAL/KETAL FORMATION): This results in the formation of an ACETAL FROM ALDEHYDES AND A KETAL FROM KETONES, which has two _______ groups attached to the same carbon.