OCH2 CH=CHCH3 OH H,O CH2Ph OCH3 H3CC—N(CH3)2 Et OH COCI CH2N2、PhCO2Ag/oH HO CH2 NH2 CH3 N-OHO C H 2 C H = C H C H 3 K O H H 2 O 16 17 N Et O H C H 2 Ph H3C CO C H 3 O C H 3 N(C H 3)2 18 C O Cl C H 2 N 2 P h C O 2 A g/EtO H 19 H O C H 2 N H 2 C H 3 H + 20 CNN H 2O H H +