Mechanism CH3 O CH Naoh O OH H2C-C-C H3C-C—C CH 0- CCl4 CH2-0 Br Ch2 oh CH CH3 HC-CC0一H3C-C-CO2H一→HC-C-CO2 ①D CH -o CH,O CH,OH ⑨DOrganic Chemistry Organic Chemistry Xiamen Xiamen University University Mechanism Mechanism H 3C C CH 2 CH 3 C NaOH CC l 4 H 3C C CH 2 CH 3 C O O H 3C C CH 2 O CH 3 CO 2 H O O Br OH H 3C C CH 2 CH 3 C O O OH H 3C C CH 2OH CH 3 CO 2