Question 1
What is the product of the following reaction?
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Reduction of carbonyls:
LiAlH4 is lithium aluminum hydride, also written as LAH. This is a hydride donor reducing agent.LiAlH4 reduces carbonyls like aldehyde, ketone, esters, etc. to corresponding alcohol molecule.
Question 2
What is the product of the following reaction?
Question 3
What is the product of the following reaction?
Answer to question 1
LiAlH4 reduces polar bonds like the C=O group of carbonyl molecules. But it can not reduces isolated alkenes or alkynes, because these are non-polar bonds. Hence in the above molecule, only the ketone reduces and forms secondary alcohol.
Hence the answer is C.
Answer to question 2
Step 1
Concept: Silver Mirror test
A silver mirror test is used to distinguish aldehyde from ketone. Aldehyde gives positive test whereas ketone donot give this test. In this test, Tollen’s reagent i.e. ammoniacal silver nitrate solution is used. It acts as mild oxidising agent and oxidizes aldehyde to acetate ion. Silver ion is reduced to metallic silver. This forms a bright silver mirror on the inner side of the container or it forms grayish-black precipitate.
R−CHO+2[Ag(NH3)2]++3OH− ———-> R−COO−+2Ag↓+2H2O+4NH3
Step 2
Since ketones do not give silver mirror test,there will be no product formed.
Answer to question 3
