In the above conversion of compound (X) to product (Y), the sequence of reagents to be used will be
(1) (i) Br2, Fe (ii) Fe, H+ (iii) LiAlH4
(2) (i) Br2(aq) (ii) LiAlH4 (iii) H3O+
(3) (i) Fe, H+ (ii) Br2(aq) (iii) HNO2 (iv) CuBr
(4) (i) Fe, H+ (ii) Br2(aq) (iii) HNO2 (iv) H3PO2
