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Standard XII

Chemistry

Synthesis of Aldehydes or Ketones from Hydrocarbons

An organic co...

Question

An organic compound (A) with molecular formula $C_{8} H_{8} O$ forms an orange-red precipitate with 2,4 DNP and gives a yellow precipitate of compound (B) on treatment with iodine and sodium hydroxide solution. Compound (A) does not give Tollen's or Fehling test but on drastic oxidation with potassium permanganate, it gives (C) which on reaction with thionyl chloride gives a compound (D) having formula $C_{7} H_{5} O C l$ . (D) on reaction with compound (E) having general formula $R_{2} C d$ gives back (A)/ Identify (A), (B), (C), (D) and (E). Also, give chemical equations for the reaction involved.

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Solution

Compound A is acetophenone.

It on reaction with $I_{2} + N a O H$ undergoes haloform reaction to form yellow coloured iodoform as a product.

When compound A reacts with $K M n O_{4}$ it undergoes oxidation to form benzoic acid (C).

When benzoic acid reacts with $S o C l_{2}$ it forms benzoyl chloride (D) as a product.

When Benzoyl chloride reacts with ( $R_{2} C d$ ) it gives corresponding ketone (acetophenone) (A) as a product.

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