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(a) Write the structural formula of the main organic product formed when ethyl acetate is treated with twice the molar quantity of ethyl magnesium bromide and the reaction mixture is poured into water. (b) Give the structures of Grignard reagent and the substrate (aldehyde or ketone) that would react to form 2,4-dimethyl pentan-3-ol. (c ) By giving one chemical reaction prove that glycerol is an alcohol. (d) Give one specific example to prove that enzymes are very specific in their action . (e ) Write down the names and structures of two compounds obtained by dehydration of ethyl alcohol. (f) List the reagents commonly used to reduce carbonyl functional groups to alcohols. (g) Give the expected reduced product from the reaction of (a) CH_(3)COCH_(2)COOH,""(b)OHC CH_(2)C OO CH_(3) (c ) CH_(3)CH_(2)COCH_(2)CH_(2)Br," "(d)p-O_(2)N-C_(6)H_(4)CHO with (i) NaBH_(4),(ii)LiAlH_(4) (h) Give the product of the oxidation with MnO_(2) of : (a) CH_(3)CH_(2)CH=CHCH_(2)OH (b) C_(6)H_(5)CH_(2)OH (c )C_(6)H_(5)CH(OH)CH_(2)CH_(2)OH (d) CH_(3)CH=CHCH_(2)CH_(2)CH_(2)OH (i) Give the product of the oxidation with Jones reagent of : (a)CH_(3)CH=CHCH(OH)CH_(3)""(b)C_(6)H_(11)CH_(2)OH |
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Answer» (f) `H_(2)//` catalyst, `LiAlH_(4),NaBH_(4),NaH`. (g) (a) `(i) CH_(3)CH(OH)CH_(2)COOH` (`ii) CH_(3)CH(OH)CH_(2)CH_(2)OH` (b) (i) `HOH_(2)C CH_(2)COOCH_(3)" " (ii) HOH_(2)C CH_(2)CH_(2)OH` (c ) (i)`CH_(3)CH_(2)CH(OH)CH_(2)CH_(2)Br` (ii) `CH_(3)CH_(2)CH(OH)CH_(2)CH_(3)` (d) (i) `p-O_(2)N-C_(6)H_(4)CH_(2)OH (ii)p-H_(2)N-C_(6)H_(4)CH_(2)OH` `[LiAlH_(4),` being a more reactive reducing agent than `NaBH_(4)`, will also reduce-COOH and -COOR to corresponding primary alcohols. `LiAlH_(4)` also reduces `-NO_(2)` to `-NH_(4)` and many alkyl halides are reduced to alkanes. ] (h) `(a) CH_(3)CH_(2)OCH=CHCHO""(b) C_(6)H_(5)CHO` (c ) `C_(6)H_(5)COCH_(2)CH_(2)OH ""(d) `NO reaction `[MnO_(2)` is a weaker oxidising agent and it selectively oxidises the -OH group of only allylic and benzylic `1^(@)` and `2^(@)` alcohols to give aldehydes. ] (i) `(a) CH_(3)CH=CHCOCH_(3)""(b)C_(6)H_(11)CHO` [The Jones reagent is a CHROMIC acid is aqueous acetone solution and sufficiently mild to oxidise alcohols into  without affecting the double bonds. ] (J) By using selective OXIDANT like, (i) `K_(2)Cr_(2)O_(7) //` dil. `H_(2)SO_(4)` (ii) copper or silver catalyst at 523K (ii) Pyridinium chlorochromate (PC C ) , made by mixing equimolar amounts of `CrO_(3)`, HCland pyridine in `CH_(2)Cl_(2)` (iv) COLLINS reagent, made up of 1 mole of `CrO_(3)` to 2 mole of pyridine in `CH_(2)Cl_(2)(` as in `MnO_(2))`. |
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