Write the structures of the following compounds.
α-Methoxypropionaldehyde
3-Hydroxybutanal
2-Hydroxycyclopentane carbaldehyde
4-Oxopentanal
Di-sec. butyl ketone
4-Fluoroacetophenone
Write the structures of products of the following reactions;
(i)
(ii)
(iii)
(iv)
Arrange the following compounds in increasing order of their boiling points.
CH3CHO, CH3CH2OH, CH3OCH3, CH3CH2CH3
Arrange the following compounds in increasing order of their reactivity in nucleophilic addition reactions.
Ethanal, Propanal, Propanone, Butanone.
Hint: Consider steric effect and electronic effect.
Benzaldehyde, p-Tolualdehyde, p-Nitrobenzaldehyde, Acetophenone.
Predict the products of the following reactions:
Give the IUPAC names of the following compounds:
Ph CH2CH2COOH
(CH3)2C = CHCOOH
Show how each of the following compounds can be converted to benzoic acid.
Ethylbenzene
Acetophenone
Bromobenzene
Phenylethene (Styrene)
Which acid of each pair shown here would you expect to be stronger?
CH3CO2H or CH2FCO2H
CH2FCO2H or CH2ClCO2H
CH2FCH2CH2CO2H or CH3CHFCH2CO2H
What is meant by the following terms? Give an example of the reaction in each case.
Cyanohydrins
Acetal
Semicarbazone
Aldol
Hemiacetal
Oxime
Ketal
Imine
2,4-DNP-derivative
Schiff’s base
Name the following compounds according to IUPAC system of nomenclature:
CH3CH(CH3)CH2CH2CHO
CH3CH2COCH(C2H5)CH2CH2Cl
CH3CH=CHCHO
CH3COCH2COCH3
CH3CH(CH3)CH2C(CH3)2COCH3
(CH3)3CCH2COOH
OHCC6H4CHO-p
Draw the structures of the following compounds.
3-Methylbutanal
p-Nitropropiophenone
p-Methylbenzaldehyde
4-Methylpent-3-en-2-one
4-Chloropentan-2-one
3-Bromo-4-phenylpentanoic acid
p,p’-Dihydroxybenzophenone
Hex-2-en-4-ynoic acid
Write the IUPAC names of the following ketones and aldehydes. Wherever possible, give also common names.
CH3CO(CH2)4CH3
CH3CH2CHBrCH2CH(CH3)CHO
CH3(CH2)5CHO
Ph-CH=CH-CHO
PhCOPh
Draw structures of the following derivatives.
The 2, 4-dinitrophenylhydrazone of benzaldehyde
Cyclopropanone oxime
Acetaldehydedimethylacetal
The semicarbazone of cyclobutanone
The ethylene ketal of hexan-3-one
The methyl hemiacetal of formaldehyde
Predict the products formed when cyclohexanecarbaldehyde reacts with following reagents.
PhMgBr and then H3O+
Tollens’ reagent
Semicarbazide and weak acid
Excess ethanol and acid
Zinc amalgam and dilute hydrochloric acid
Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction.
(i) Methanal
(ii) 2-Methylpentanal
(iii) Benzaldehyde
(iv) Benzophenone
(v) Cyclohexanone
(vi) 1-Phenylpropanone
(vii) Phenylacetaldehyde
(viii) Butan-1-ol
(ix) 2,2-Dimethylbutanal
How will you convert ethanal into the following compounds?
Butane-1,3-diol
But-2-enal
But-2-enoic acid
Write structural formulas and names of four possible aldol condensation products from propanal and butanal. In each case, indicate which aldehyde acts as nucleophile and which as electrophile.
An organic compound with the molecular formula C9H10O forms 2,4-DNP derivative, reduces Tollens’ reagent and undergoes Cannizzaro reaction. On vigorous oxidation, it gives 1,2-benzenedicarboxylic acid. Identify the compound.
An organic compound (A) (molecular formula C8H16O2) was hydrolysed with dilute sulphuric acid to give a carboxylic acid (B) and an alcohol (C). Oxidation of (C) with chromic acid produced (B). (C) on dehydration gives but-1-ene. Write equations for the reactions involved.
Arrange the following compounds in increasing order of their property as indicated:
Acetaldehyde, Acetone, Di-tert-butyl ketone, Methyl tert-butyl ketone (reactivity towards HCN)
CH3CH2CH(Br)COOH, CH3CH(Br)CH2COOH, (CH3)2CHCOOH, CH3CH2CH2COOH (acid strength)
Benzoic acid, 4-Nitrobenzoic acid, 3,4-Dinitrobenzoic acid, 4-Methoxybenzoic acid (acid strength)
Give simple chemical tests to distinguish between the following pairs of compounds.
Propanal and Propanone
Acetophenone and Benzophenone
Phenol and Benzoic acid
Benzoic acid and Ethyl benzoate
Pentan-2-one and Pentan-3-one
Benzaldehyde and Acetophenone
Ethanal and Propanal
How will you prepare the following compounds from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom
Methyl benzoate
m-Nitrobenzoic acid
p-Nitrobenzoic acid
Phenylacetic acid
p-Nitrobenzaldehyde.
How will you bring about the following conversions in not more than two steps?
Propanone to Propene
Benzoic acid to Benzaldehyde
Ethanol to 3-Hydroxybutanal
Benzene to m-Nitroacetophenone
Benzaldehyde to Benzophenone
Bromobenzene to 1-Phenylethanol
Benzaldehyde to 3-Phenylpropan-1-ol
Benazaldehyde to α-Hydroxyphenylacetic acid
Benzoic acid to m- Nitrobenzyl alcohol
Describe the following:
Acetylation-
Cannizzaro reaction
Cross aldol condensation
Decarboxylation
Complete each synthesis by giving missing starting material, reagent or products
CH3COCH2COOC2H5
Give plausible explanation for each of the following:
Cyclohexanone forms cyanohydrin in good yield but 2,2,6-trimethylcyclohexanone does not.
There are two –NH2 groups in semicarbazide. However, only one is involved in the formation of semicarbazones.
During the preparation of esters from a carboxylic acid and an alcohol in the presence of an acid catalyst, the water or the ester should be removed as soon as it is formed.
An organic compound contains 69.77% carbon, 11.63% hydrogen and rest oxygen.
The molecular mass of the compound is 86. It does not reduce Tollens’ reagent but forms an addition compound with sodium hydrogensulphite and give positive iodoform test. On vigorous oxidation it gives ethanoic and propanoic acid. Write the possible structure of the compound.
Although phenoxide ion has more number of resonating structures than carboxylate ion, the carboxylic acid is a stronger acid than phenol. Why?
