CBSE Class 12 · 2017 · Aldehydes Ketones and Carboxylic AcidsLong Answer

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(a) Write the reactions involved in the following:
i) Etard reaction ii) Stephen reduction
(b) How will you convert the following in not more than two steps?
i) benzoic acid to benzaldehyde
ii) acetophenone to benzoic acid
iii) ethanoic acid to 2-hydroxyethanoic acid

Solution

(a)(i)

C_{6} H_{5} C H_{3} Cr O_{2} C l_{2} /C S_{2} H_{3} O^{+} C_{6} H_{5} CHO

(ii)

RCN SnC l_{2} /HCl RCH = NH \cdot HCl H_{3} O^{+} RCHO

(b)(i)

C_{6} H_{5} COOH SOC l_{2} C_{6} H_{5} COCl H_{2} /Pd - BaS O_{4} C_{6} H_{5} CHO

(ii) Haloform cleavage then acidification:

C_{6} H_{5} COC H_{3} I_{2} /NaOH C_{6} H_{5} COONa H^{+} C_{6} H_{5} COOH

(iii) HVZ then hydrolysis:

C H_{3} COOH C l_{2} /red P ClC H_{2} COOH KOH (aq); H^{+} HOC H_{2} COOH

CBSE Class 12 Board · 2017 · Subjective

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