Consider the following reactions: Reaction I: underset((1.0" mole"))(CH_(3)-overset(O)overset(||)(C)-CH_(3)) underset("aqueous NaOH")overset(Br_(2)(1.0" mole"))to Reaction II: CH_(3)-overset(O)overset(||)(C)-CH_(3) underset(CH_(3)COOH)overset(Br_(2)("1.0 mole"))to (a) Discuss briefly the composition of the reaction mixture in each case. (b) Discuss the mechanism of the reaction under basic conditions.

Consider the following reactions: Reaction I: underset((1.0" mole"))(

1.	Consider the following reactions: Reaction I: underset((1.0" mole"))(CH_(3)-overset(O)overset(\|\|)(C)-CH_(3)) underset("aqueous NaOH")overset(Br_(2)(1.0" mole"))to Reaction II: CH_(3)-overset(O)overset(\|\|)(C)-CH_(3) underset(CH_(3)COOH)overset(Br_(2)("1.0 mole"))to (a) Discuss briefly the composition of the reaction mixture in each case. (b) Discuss the mechanism of the reaction under basic conditions.
Answer» Solution :(b) Step 1. In presence of a base, the three weakly ACIDIC `alpha`-hydrogens of ACETONE are successively replaced by Br atoms to form `alpha, alpha, alpha`-tribromoacetone (I). Step 2. The `alpha, alpha, alpha`-tribromocetone (I) thus formed undergoes nucleophilic attack by `OH^(-)` ion on the C=O group followed by cleavage of the `C-CBr_(3)` bond and proton to ultimately give bromoform (II) and `CH_(3)COO^(-)` ion.