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ABC CLASSES FOR IIT-JEE

ALDEHYDES AND KETONES

D.P.P. - 4

1. (i) A ketone (A) which undergoes a haloform reaction gives compound (B) on reduction B on

heating with sulphuric acid gives compound C. Which forms mono-ozonide D. The compound d

on hydrolysis in presence of zinc dust gives only acetaldehyde. Identify A, B and C. Write down

the reacn involved.

2. An organic compound (A) having molecular formula C6H10O, on treatment with methyl

magnesium iodide followed by acid treatment for a long time gave (B). (B) on ozonolysis yielded

(C) and (C) on treatment with a dilute basic solution gave 1 – acetyl cydopentere. (B) on reaction

with HCl gave (D). Identify (A) to (D) and show the mechanism involved in conversion of (C) to 1-

acetyl cyclopentene.

3. An aromatic compound (A), C8H4Br reacts with H2C(COOC2H5)2 in the presence of C2H5O-Na+ to

give (B) compound (B) on refluxing with dil H2SO4 give (D). The compound (D) is a dibasic acid

but on heating does not give an anhydride. It forms a mono nitro derivative (E). in which all the

substituents are at equidistant from one another. Give structures of (A) to (E).

4. When t – butanol and n – butanol are separately treated with a few drops of dil. KMnO4 in one case only the purple colour disappears and a brown ppt is formed. Which of the two alcohols gives

above reaction and what is brown ppt?

5. Treatment of comp. A (C8H10O) with chromic acid/ pyridine gives B (C8H8O) which reacts with

bromine yielding C(C8H6OBr2). (C) generates (D) (C8H8O3) upon treatment with alkali and

subsequent acidification. Oxidation of D with alkaline KMnO4 and subsequent acidification gives

benzoic acid. Treatment of (B) with SeO2 gives E (C8H6O2) which also affords D when treated with

alkali followed by acidification. Identify A, B, C, D and E with proper reasoning.

6. Identify the product

7. (i) Assuming the absence of any steric hindrance list the following alkenes in deoreasing order of reactivity towards electrophillic addition.

(a) Cl CH2CH = CH2 (b) Me2C = CH2 (c) CH3CH = CH2 (d) H2C = CHCl.

Explain your order.

(ii) Assume that anti elimination is favoured, illustrate the stereo specificity of the E – 2

dehydrohalogenation by predicting the products formed from (a) meso and (b) either of the

enantiomers of 2, 3 – dibromo butane. Use of wedge – saw horse and Newmann projections.

8. Two isomeric substances (X) and (Y) have the molecular formula C3H6O. On mild oxidation (X)

gives a monobaric acid (Z), sadium salt of which on heating with caustic soda produces ethane. On

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ABC CLASSES 126,2nd Floor , Kingsway Camp , Delhi-11009,Ph:011-47041845, www.abcclasses.in

similar treatment namely mild oxidation (Y) remains unaffected but readily reacts with I2 and

NaOH solution producing iodoform what are the compounds (X), (Y) and (Z)?

9. Identify A to J in the following:

(a) (b)

10. Identify A to F in the following sequence of reactions.