HighT (12) =一品地0 w-○=sa,o4s0 入0ysm 4.Write stepwise and reasonable mechanisms for the following reactions(20) 0今cH,+ck500℃ ◇·3 (9) (10) (11) (12) (13) (14) (15) O O O + High T 1. Na, NH3 (l) 2. EtOH OH PCC, CH2Cl2 HgSO4, H2O, H2SO4 O Br2, hv 4. Write stepwise and reasonable mechanisms for the following reactions (20). CH3 + Cl2 500 oC (1) Cl OH + HBr Br (+) (2)