(a) `H_(3)C-H_(2)C-underset(OH)underset(|)(C)H-CH_(3)overset(CrO_(3))toH_(3)C-underset("Butan-2-one")(H_(2)C-underset(O)underset(||)(C)-CH_(3))`
(b) `H_(3)C-CH_(2)-underset(OH)underset(|)(C)H-CH_(3)-+SOCl_(2)toH_(3)C-underset("2-Chlorobutane")(CH_(2)-underset(Cl)underset(|)(C)H-CH_(3))`.