Summary of Organic Compounds

Ester

• Alcohol + carboxylic acid --> (conc. sulfuric acid)
• Hydrolysis of ester:
• A = Aqueous sulfuric acid (acidic condition)
• --> carboxylic acid + alcohol
• B = Aqueous sodium hydroxide (basic condition)
• --> carboxylate ion + alcohol

Fats, Oils (Big Esters)

• Triglycerides:
• glycerol + carboxylic acid --> triglyceride + water
• Hydrolysis of triglycerides:
• A = Aqueous sulfuric acid (acidified water) (acid condition)
• --> glycerol + 3 carboxylic acid
• B = Aqueous sodium hydroxide (basic condition)
• --> glycerol + 3 carboxylate ion (sodium carboxylate salt - soap)

Hydrolysis of polymer w/ ester link (multiple ester bonds)

• A = Aqueous sulfuric acid (acidic condition)
• --> alcohol + carboxylic acid
• B = Aqueous sodium hydroxide (basic condition)
• --> alcohol + carboxylate ion

Polymers

• Alcohol + carboxylic acid --> polymer with ester link + water
• Alcohol + acid chloride --> ester link + HCl
• Amine + carboxylic acid --> amide/peptide link + water
• Amine + acid chloride --> amide/peptide link + HCl

Amides

• Acyl chloride + ammonia --> amide + HCl (preferred method of making amides as it is a violent reaction).
• Carboxylic acid + ammonia (heat)--> salt (heat)--> amide
• Ketone + ammonia --> amide + OH-R
• Ketone + amine --> secondary amide with amide/peptide link

Amide Hydrolysis

• A = Aqueous sulfuric acid (acidic condition)
• --> carboxylic acid + ammonium (acid formed in acidic condition)
• B = Aqueous sodium hydroxide (basic condition)
• --> carboxylate ion (with Na+) + ammonia (base is formed in basic condition - acid donated H+ ion in basic condition)

Hydrolysis of polymer w/ amide link

• A = Aqueous sulfuric acid (acidic condition)
• --> carboxylic acid + R-NH3+ (basic end of molecule NH2 accepts H+ to become NH3+)
• B = Aqueous sodium hydroxide (basic condition)
• --> carboxylate ion (with Na+) + R-NH2 (base is formed in basic condition - acid part donates H+)

Hydrolysis of protein (breaking amide/peptide link)

• A = Aqueous sulfuric acid (acidic condition)
• --> HOCH2-CH(NH3+)-COOH + COOH-CH2-NH3+ (amine is base so accepts H+ to become NH3+)
• B = Aqueous sodium hydroxide (basic condition)
• --> HOCH2-CH(NH2)-COO-(Na+) + NH2-CH2-COO-(Na+) (acidic end of acid donated H+ - base end formed in basic condition)

Aldehydes

• Can be oxidised to form carboxylic acids.
• Acidified dichromate (orange --> green)
• Acidified permanganate (purple --> colourless)
• Tollen's Reagent Ag+ (aq) + e- --> Ag (s) (colourless --> thin black precipitate or silver mirror)
• Fehlings/Benedicts Cu2+ --> Cu2O (blue --> brick red)
• Can be reduced back to primary alcohol using NaBH4.

Ketones

• NO FURTHER OXIDATION
• Can be reduced back to secondary alcohol using NaBH4
• *Still mention negative test result*
• e.g. this is a ketone because there was no colour change

Lucas Reagent ZnCl2/HCl conc.

• ZnCl2 is a catalyst, HCl does the reducing.
• Lucas Reagent is used to distinguish alcohols.
• Alcohol --> Haloalkane
• Colourless --> Cloudy (due to insoluble haloalkane)
• Tertiary - fastest
• Secondary - slower
• Primary - no reaction

Alcohols

• 1. PRIMARY ALCOHOL oxidised by acidified dichromate/permanganate. First to an ALDEHYDE then to a CARBOXYLIC ACID.
• The reverse of this reaction is a reduction using NaBH4. The aldehyde is reduced to make a primary alcohol.
• 2. SECONDARY ALCOHOL oxidised by acidified dichromate/permanganate to a KETONE.
• The reverse of this reaction, a reduction using NaBH4. The ketone is reduced to make a secondary alcohol.
• 3. Nucleophilic substitution by PCl3, PCl5 or SOCl2 to make a HALOALKANE - works best with primary or secondary
• 4. Elimination by concentrated sulfuric acid forms an ALKENE (water removed). If asymmetrical, major and minor product formed using Markovnikof's Rule.
• 5. Addition to ALKENE to make an ALCOHOL - dilute sulfuric acid or acidified H2O.
• This forms major and minor product (H atom goes onto carbon with more hydrogen atoms, OH goes on other carbon)
• 6. Lucas Reagent (see slide)
• PRIMARY AND SECONDARY ALCOHOLS WILL BE OXIDISED BY TOLLENS OR FEHLINGS/BENEDICTS.

Haloalkanes

• 1. Substitution KOH (aq) must be aqueous conditions, can use NaOH (aq) to make an ALCOHOL.
• 2. Nucleophilic substitution NH3 in ethanol
• 3. Substitution - bigger amine
• 4. Elimination KOH (alc) - forms major and minor product if asymmetrical

Carboxylic acids

• 1. Acid Base
• Acid + Base --> Salt + Water
• Acid + Carbonate --> Salt + Water + Carbon dioxide
• 2. Substitution PCl5, PCl3 or SOCl2 to make an ACID CHLORIDE. Cannot be done with HCl as it contains water and would react violently.
• Ethanoic acid (R-COOH) -----> Ethanoyl chloride (R-COCl)
• 3. Substitution NH3 - 2 stage reaction to make an AMIDE (slow reaction)
• Ethanoic acid + NH3 ------> Ethanoate ion (w/ NH4+) --(heat)---> Ethanamide (R-CONH2)