question_answer 22)

                How will you bring about the following conversion in notmore than two steps? (i) Propanone to propene (ii) Benzoic acid to benzaldehyde (iii) Ethanol to 3-hydroxy butanal (iv) Benzene to m-nitroacetophenone (v) Benzaldehyde to benzophenone (vi) Bromobenzene to 1-phenyl ethanol (vii) Benzaldehyde to 3-phenyl propan-1-ol (viii) Benzaldehyde to -hydroxy phenyl acetic acid (ix) Benzoic acid to w-nitrobenzyl alcohol (i) Alcohols readily gives alkene on dehydration, so first convert ketone into alcohol by reduction then do dehydration, (ii) Benzaldehyde is easily obtained from benzoyl chloride so convert benzoic acid into benzoyl chloride and then do Rosenmund'sreduction. (iii) Carbonyl compounds gives a compound having double carbon atomsthan the parent compounds, if undergo aldol condensation, so firstconvert alcohol to aldehyde by oxidation and then do Aldol condensation. (iv) , is m-directing group, so do Friedel Craft acylation to introduce , group followed by nitration. (v) (a) Oxidation to convert into acid. (b) Heating of calcium salt. (vi) (a) Formation of Grignard reagent, (b) Treating with  and hydrolysis. (vii) Perkin's reaction followed by reduction. (viii) Aldol condensation as it gives -hydroxyaldehyde which is oxidized to get acid. (ix) Nitration followed by reduction.  

Answer:

(i) Propanone to propene (ii) Benzoic acid to benzaldehyde     (iii) Ethanol to 3-hydroxybutanal     (iv) Benzene to m-nitroacetophenone                   (v) Benzaldehyde to benzophenone     (vi) Bromobenzene to 1-phenylethanol     (vii) Benzaldehyde to 3-phenyl propan-1-ol             (viii) Benzaldehyde to -hydroxy phenyl acetic acid     (ix) Benzoic acid to m-nitrobenzyl alcohol