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Draw the structure and name the product formed if the following alcohols are oxidised. Assume than an excess of oxidising agent is used. (i) CH_(3)CH_(2)CH_(2)CH_(2)OH (ii) 2-butenol (iii) 2-methyl-1-propanol. |
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Answer» <P> Solution :(i) OXIDATION of saturated alcohols is usually carried out with strong oxidising gents such as `K_(2)Cr_(2)O_(7)//H_(2)SO_(4)` or `KMnO_(4)//OH^-` which first gives the corresponding aldehydes annd then the corresponding acids. For example,`underset("1-Butanol")(CH_(3)CH_(2)CH_(2)CH_(2)OH) underset([O])overset(K_(2)Cr_(2)O_(7)//H_(2)SO_(4))to underset("BUTANAL")(CH_(3)CH_(2)CH_(2)CHO) underset([O])overset(K_(2)Cr_(2)O_(7)//H_(2)SO_(4))to underset("Butanoic acid")(CH_(3)CH_(2)CH_(2)COOH)` (ii) Oxidation of unsaturated alcohols such as 2-butenol is carried out with `PC C//CH_(2)Cl` because oxidation with stronger oxidising aents such as `K_(2)Cr_(2)O_(7)//H_(2)SO_(4)` or `KMnO_(4)//OH^(-)` will bring about cleavage at the double bond. further, with `PC C//CH_(2)Cl_(2)`, oxidation stops at the aldehyde stage evenn if excess o the reagent is used. `underset("2-Butenol")(CH_(3)-CH=CH-CH_(2)OH) underset([O])overset(P C C//CH_(2)Cl_(2))to underset("2-Butenal")(CH_(3)-CH-CHO)` (iii) `underset("2-Methyl-1-propanol")(CH_(3)-overset(CH_(3))overset(|)(C)H-CH_(2)OH) underset([O])overset(K_(2)Cr_(2)O_(7)//H_(2)SO_(4))to underset("2-Methylpropanal")(CH_(3)-overset(CH_(3))overset(|)(C)H-CHO) underset([O])overset(K_(2)Cr_(2)O_(7)//H_(2)SO_(4))to underset("2-Methylpropanoic acid")(CH_(3)-overset(CH_(3))overset(|)(C)H-COOH)` |
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