(12) 人=一/2：品N0 ) PCC.CHzCl2 人人0 00 (+) 5.Write stepwise and reasonable mechanisms for the following reactions (20). 0今cH+ch500℃ c1-C150c、2G 今H+c→入·+c 入·+ck→入+ 2CF CI-CI 2入·→入入 今·+c→今d 4 (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 O O O H H (+) O O O Br (+) 5. Write stepwise and reasonable mechanisms for the following reactions (20). CH3 + Cl2 500 oC (1) Cl Cl Cl 500o C 2 Cl. H + Cl. + HCl + Cl2 Cl + Cl. 2 Cl Cl Cl . + Cl. Cl 2