Aldehydes, Ketones and Carboxylic Acids

1. Cyclohexanone forms cyanohydrin in good yield because the ketonic group has very less steric hindrance at both the ortho position but 2,2,6 tri methyl cyclohexanone have high steric hindrance which reduces the attack from CN nucleophile.

2. Only one Amino group is involved in the resonance structure of semicarbazide hence e^- density on NH₂ group decreases & it can't act as a nucleophile. But another NH₂ group can attack as a nucleophile to form semicarbazones.

3. It is the reversible reaction hence if we don't remove the water or ester the reaction may proceed in backward direction, for that It is essential the water or ester as soon as formed

1. When 1- phenyl ethane is oxidized with a strong oxidizing agent like KMnO₄, it forms a benzoic acid ion.

2. When phthalic acid is treated with SoCl₂ it chlorinates both carboxyl group to form ptthaloyl chloride.

3. When benzaldehyde is treated with semicarbazide to form benzaldehyde semicarbazone.

4. When benzene is mixed with benzoyl chloride in presence of Anhyd.AlCl₃ to give benzophenone.

5. When 4-oxocyclohexanecarbeldehyde is treated with tollens reagent it gets oxidized to carboxylate anion  as it is aldehyde it reduces tollens reagent.

6. When 2-formyl benzoic acid is treated with NaCN it produces 2-[1-hydroxycyanomethyl]benzoic acid.

7. When benzaldehyde and propanal mixed equally in presence of Dil.NaOH it forms 2-methyl-3-phenyl-prop-2-enal.

8. When Ethyl 3-oxobutanate is treated with sodium borohydride it converts oxo to hydroxyl.

9. When cyclohexanol is oxidized with CrO₃ it forms cyclohexanone.

10. When methylenecyclohexane undergo hydroboration oxidation reaction it will form alcohol. Further treating with oxidizing agent PCC it converts into aldehyde.

When cyclohexylidenecyclohexane undergo ozonolysis it will form cyclohexanone.

 

 

 

 

1. Acetylation refers to the process of introducing an acetyl group (resulting in an acetoxy group) into a compound, namely the substitution of an acetyl group for an active hydrogen atom. A reaction involving the replacement of the hydrogen atom of a hydroxyl group with an acetyl group (CH₃CO) yields a specific ester, the acetate. Acetic anhydride is commonly used as an acetylating agent reacting with free hydroxyl groups., this reaction is usually carried out in the presence of base like pyridine.

2. Aldeydes having no α-H undergo the disproportion reaction in the presence of Strong alkali, it is a chemical reaction that involves the base-induced disproportionation of a non-enolizable aldehyde This reaction is known as Cannizzaro reaction.In this reaction two molecules of aldehyde is reacted, 1 is reduced to alcohol and other is oxidized to carboxylic acid.

3. When aldol condensation is carried out between two different aldehydes or two different ketones, or one aldehyde and one ketone this reaction is called as CROSS ALDOL CONDENSATION, if both the reactant is having α H then 4 products are formed ( 2 self aldol& 2 cross aldol)

4. Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO₂). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. in this reaction carbon dioxide is released.

 

1. When propanone reacts with NaBH₄ it will form propan-2-ol.This alcohol is dehydrated to form propene.

2. When benzoic acid is treated with SOCl₂ it chlorinates the acid. After controlled hydrogenation it forms benzaldehyde

3. When ethanol is treated with Cu at 573 k, it will oxidize to ethanal. When ethanal is treated with Dil.NaOH it will form 3-Hydroxy butanal

4. After frieadal craft acylation of benzene it will convert into acyl benzene. And further treating with nitrating mixture it forms m-nitroaceto phenone .

5. When benzaldehyde is oxidized with dichromate and treated with calcium carbonate it forms calcium salt. And after dry distillation it gets converted into benzophenone.

6. When bromobenzene reacts with Mg in dry ether it forms Grignard reagent, further treating with ethanal in acidic condition it forms 1-phenyl ethanol.

7. When benzaldehyde is mixed with ethanal in presence of Dil. NaOH and then heating it in acidic condition, and after that hydrogenation it forms 3-phenylpropan-1-ol.

8. Benzaldehyde is mixed with HCN at pH 9-10, and further treating it with Water at slightly acidic condition it forms? -Hydroxyphenylacetic acid

9. When benzoic acid reacted with nitrating mixture it forms m- nitrobenzoic acid further it treated with SOCl₂ it chlorinate the acidic COOH group. And reacting with NaBH₄ further it get converted into m-nitroenzyl alcohol.

 

1. When benzene is treated with Br₂ In presence of ferric bromide (brominating agent) they form bromobenzene. When bromobenzene is treated with Mg in ether it will form Grignard reagent, and if the CO₂ is treated with Grignard reagent (in acidic condition) it will form benzoic acid. After esterification reaction in presence of methanol it will form methyl benzoate.

2. When benzene is treated with Br₂ In presence of ferric bromide (brominating agent) they form bromobenzene. When bromobenzene is treated with Mg in ether it will form Grignard reagent, and if the CO₂ is treated with Grignard reagent (in acidic condition) it will form benzoic acid. When nitrating mixture is treated with benzoic acid it will form m-Nitrobenzoic acid.

3. After friedel craft acylation of benzene it will form toluene, after nitration it forms p-nitro toluene as major product, after oxidation of this compound with KMnO₄ in acidic conditions it forms p-Nitrobenzoic acid.

4. After friedel craft acylation of benzene it will form toluene, after bromination with NBS it forms benzyl bromide, when benzyl bromide reacts with Alc.KCN benzyl cyanide forms . Acidic hydration it forms phenylacetic acid.

5. After friedel craft acylation of benzene it will form toluene, after nitration it forms p-nitro toluene as major product. After reacting it with chromyl chloride it will forms chromyl complex. When this complex treated under acidic condition it forms p-nitro benzaldehyde,

a )Tollen's test –Due to oxidizing nature of aldehydes they get easily oxidized, wheareas in case of ketones they are not readily

oxidizable. And tollens test exploits this fact, [Ag (NH₃)₂]⁺ is used as reagent Ag mirror is formed during this reaction

b) fehling test- aldehyde reduces the fehling solution to form red brow precipitate of Cu₂O. Fehling's solution is a chemical reagent used to differentiate between water-soluble carbohydrate and ketone functiona groups, and as a test for reducing sugars and non-reducing sugars, supplementary to the Tollens' reagent test.

2. Iodoform test- Methyl ketones give positive iodoform test, so when acetophenone react with NaOI it forms Yellow ppt. ofIodoform. Whereas the benzophenone will not give ppt. of iodoform. Iodoform is CHI₃ tri iodo methane. It forms only in the case when NaOI is trated with methyl ketone.

C₆H₅COCH₃+NaOI ?  C₆H₅COONa+ CHI₃+NaOH

3. When phenol reacts with FeCl₃ it forms violet coloured complex, whereas the benzoic acid not,

 

4. When we add NaHCO₃ to acid solution it will produce effervescence of CO₂ gas, hence benzoic acid will give CO₂ gas and ethyl benzoate will not.

5. Iodoform test – as acetophenone is methyl ketone it will form

CHI₃ during iodoform test, Iodoform is CHI₃ tri iodo methane. It forms only in the case when NaOI is trated with methyl ketone, this is confirmatory test for methyl ketones.

6. Ethanal is methyl aldehyde, it gives positive iodoform test on reacting with NaOI, Whereas the propanal can't

1. Di-tertbutyl, ketone

2. +I effect donates e^- . Br group will show +I effect along the chain but as I effect is distance dependent effect it will die as the distance increase.+I effect of alkyl group will reduce the acidity of a compound whereas –I effect will increase the acidity, I effects are distance dependent, correct order will be (CH₃)₂CHCOOH< CH₃CH₂CH₂COOH< CH₃CH (Br)CH₂COOH < CH₃CH₂CH (Br)COOH.

3. As we know the electron releasing groups (ERG) reduces the acidic strength of the compound (via inductive effect) whereas the electron withdrawing group (EWG) will increase the acidic strength of compound, and methoxy group is ERG, and nitro group is EWG, Increasing number of EWG will increase the effect and acidity too. Hence final order will be Methoxy benzoic acid< Benzoic acid<4-Nitrobenzoic acid<3,4-Dinitrobenzoic acid.