Overoxidation of primary alcohols to carboxylic acids is caused by the water presentin

Chapter 17, Problem 40

(choose chapter or problem)

Overoxidation of primary alcohols to carboxylic acids is caused by the water presentin the usual aqueous acidic Cr(VI) reagents. The water adds to the initial aldehyde productto form a hydrate, which is further oxidized (Section 17-6). In view of these facts, explain thefollowing two observations. (a) Water adds to ketones to form hydrates, but no overoxidationfollows the conversion of a secondary alcohol into a ketone. (b) Successful oxidation of primaryalcohols to aldehydes by the water-free PCC reagent requires that the alcohol be added slowlyto the Cr(VI) reagent. If, instead, the PCC is added to the alcohol, a new side reaction forms anester. This is illustrated for 1-butanol.OBCH3CH2CH2CH2OH uuuvvy CH3CH2CH2COCH2CH2CH2CH3(c) Give the products expected from reaction of 3-phenyl-1-propanol and water-free CrO3(1) when the alcohol is added to the oxidizing agent and (2) when the oxidant is added to thealcohol.