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How willyou bring about the following conversions in not more than two steps ? (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 - Phenylpropan -1- ol (viii) Benzaldehyde to alpha- Hydroxyphenylacetic acid (ix) Benzoic acid to m - Nitrobenzyl alcohol. |
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Answer» Solution :(i) Propanone to Propene : `underset("Propanone")(CH_(3)-overset(O)overset(||)C-CH_(3))overset(NaBH_(3))rarr underset("Propan -2- ol")(CH_(3)-overset(OH)overset("|")"CH"-CH_(3))overset("conc. "H_(2)SO_(4))underset(443K)rarr underset("Propene")(CH_(3)-CH=CH_(2))` (ii) Benzoic acid to Benzaldehyde :  (iii) Ethanol to 3 - Hydroxybutanal : `underset("Ethanol")(CH_(3)CH_(2)OH)overset("PCC")underset(underset("chlorochromate")("Pyridinium"))rarr underset("Ethanal")(CH_(3)CHO) underset(underset("CONDENSATION")underset("Aldol"))overset("Dil. NaOH")rarr underset("3 - Hydroxybutanal")(CH_(3)-overset(OH)overset("|")"CH"-CH_(2)CHO)` (iv) Benzene to m - Nitroacetophenone :  (v) Benzaldehyde to Benzophenone : `underset("Benzaldehyde")(C_(6)H_(5)CHO)+[O] overset(K_(2)Cr_(2)O_(7))underset(H_(2)SO_(4))rarr underset("Benzoic acid")(C_(6)H_(5)COOH)overset(SOCl_(2))rarr C_(6)H_(5)COCl overset(C_(6)H_(6))underset("ANHY. "AlCl_(3))rarr underset("Benzophenone")(C_(6)H_(5)COC_(6)H_(5))` (vi) BROMOBENZENE to1 - Phenylethanol :   (viii) Benzaldehyde to `alpha-` Hydroxyphenylacetic acid : `underset("Benzaldehyde")(C_(6)H_(5)CHO)+HCNrarr underset("cyanohydrin")underset("Benzaldehyde")(C_(6)H_(5)-overset(OH)overset("|")"CH"-CN)overset(H^(+)//H_(2)O)underset("Hydrolysis")rarrunderset("(Mendelic acid)")underset("acetic acid")underset(alpha- "hydroxyphenyl")(C_(6)H_(5)-overset(OH)overset("|")"CH"-COOH)` (ix) Benzoic acid to m - Nitrobenzyl alcohol : 
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