EtONa H209 O 5. HCOEt + Ch2 COEt HCCH, COEt Etoh 79% EtONa H,O COEt CH3 COEt Etoh CCH COEt 5570Organic Chemistry Organic Chemistry Xiamen Xiamen University University HCOEt O CH 3COEt O + EtOH EtONa H 2 O H + HCCH 2COEt O O 79% COEt O CH 3COEt O + EtOH EtONa H 2 O H + CCH 2COEt O O 55 70