EtO- CH.CCH3 H20 HC-CH2CCH3 Et0 0 C2H5O-C-COC2H5 H-CH2CCH3 H20 CHs0-C-C-CH2CCH3 0 0 -C0 C2H5O-C-CH2CCH3 △ 0 C2H5O-C OC2H5 H-CH2CCH3 NaH HO.C2H5O-C-CH2CCH3 Cc2s+cH,CcH NaH,HO HC-OC2H5 + H-CH2CCH3 O O O O HC-CH2CCH3 C2H5O-C-C-OC2H5 + H-CH2CCH3 O O O O O O C2H5O-C-C-CH2CCH3 O O C2H5O-C-CH2CCH3 O O C2H5O-C-OC2H5 + H-CH2CCH3 O O C2H5O-C-CH2CCH3 O O C-OC2H5 + H-CH2CCH3 O O C-CH2CCH3 NaH EtO￾EtO￾NaH H2O H2O H2O H2O -CO