$\begin{array}{1 1}(a)\;(1)HSCH_2CH_2SH,dry HCl,(2)Raney\;Ni&(b)\;(1) 9-BBN,(2) HO-CH_2-CH_2-NH_2\\(c)\;(1) 4-BBN,(2) HO-CH_2-CH_2-SH&(d)\;(1)NaHSO_3,(2) H_3O^\oplus\end{array}$
