Identify the correct reagents that would bring about the following transformation.
   
1. \(\text { (i) } \mathrm{BH}_3\)
     \((ii) \mathrm{H}_2 \mathrm{O}_2 / \stackrel{\ominus}{\mathrm{OH}}\)
    \(\text { (iii) } \mathrm{P C C}\) 
2. \(\text { (i) } \mathrm{BH}_3\)
     \((ii) \mathrm{H}_2 \mathrm{O}_2 / \stackrel{\ominus}{\mathrm{OH}}\)
    \(\text { (iii) alk. } \mathrm{KMnO}_4\)
    \(\text { (iv) } \mathrm{H}_3 \mathrm{O}^{+}\)
3. \(\text { (i) } \mathrm{H}_2 \mathrm{O} / \mathrm{H}^{+}\)
    \(\text { (ii) } \mathrm{P C C}\)
4.  \(\text { (i) } \mathrm{H}_2 \mathrm{O} / \mathrm{H}^{+}\)
     \(\text { (ii) } \mathrm{CrO}_3\)