Carbohydrates

Introduction to Carbohydrates

Carbohydrates are a major class of organic compounds composed of carbon, hydrogen, and oxygen. They serve as energy sources and structural components in living organisms.

• Definition: Carbohydrates are polyhydroxy aldehydes or ketones, or compounds that yield such molecules upon hydrolysis.

• General Formula: Most carbohydrates have the empirical formula .

• Classification:

  • Monosaccharides: Simple sugars (e.g., glucose, fructose).

  • Disaccharides: Two monosaccharide units (e.g., sucrose, lactose).

  • Polysaccharides: Many monosaccharide units (e.g., starch, cellulose).

• Example: Glucose is a common monosaccharide with the structure .

Carboxylic Acids

Properties and Structure of Carboxylic Acids

Carboxylic acids are organic compounds containing the carboxyl functional group (-COOH). They are widely found in nature and play key roles in biochemistry.

• General Structure: , where R is an alkyl or aryl group.

• Acidity: Carboxylic acids are weak acids; they dissociate in water to form carboxylate ions and hydronium ions.

• Equation:

• Physical Properties: Typically have higher boiling points due to hydrogen bonding.

• Example: Acetic acid () is found in vinegar.

Carboxylic Acid Derivatives

Types and Reactivity of Carboxylic Acid Derivatives

Carboxylic acid derivatives are compounds in which the hydroxyl group of the carboxylic acid is replaced by another group. They are important intermediates in organic synthesis.

• Main Types:

  • Esters ()

  • Amides ()

  • Anhydrides ()

  • Acid Chlorides ()

• Reactivity: Reactivity depends on the leaving group; acid chlorides are most reactive, amides are least.

• General Reaction: (where X = Cl, OR, NH_2, etc.)

• Example: Ethyl acetate () is an ester used as a solvent.

Enolates, Enols, and Enamines

Structures and Reactivity of Enolates, Enols, and Enamines

Enolates, enols, and enamines are important intermediates in organic reactions, especially in carbon-carbon bond formation.

• Enol: A compound with a hydroxyl group bonded to a carbon-carbon double bond. General Structure:

• Enolate: The conjugate base of an enol, formed by deprotonation at the alpha-carbon of a carbonyl compound. General Structure:

• Enamine: A compound with an amino group attached to a carbon-carbon double bond. General Structure:

• Formation:

  • Enols form by tautomerization of carbonyl compounds.

  • Enolates form by treatment of carbonyl compounds with a base.

  • Enamines form by reaction of aldehydes/ketones with secondary amines.

• Example: Acetone enolate is formed by deprotonation of acetone () at the alpha position.

Additional info: The original notes only listed topic headings. Academic context, definitions, examples, and tables have been added to create a self-contained study guide.