KOH CH3h2CHOH SN2 HoO Eto CH 3)2 CHBr Etoh (CH3) CHOEt CH3 CH=CH2 20 80%E2 NanH, Ch2=CH E2 Etoh CH3)3CBr 25(CH3)3COEt+(CH3)2C=CH 81% 19%E2 Eto EtOH (CH3)3 COEt +(CH3)2C=CH 2 ⑨D 25 93%E2Organic Chemistry Organic Chemistry Xiamen Xiamen University University (C H 3 ) 2CHBr KOH H 2 O Et O - EtOH NaNH 2 (C H 3 ) 2CHOH (C H 3 ) 2CHOEt + C H 3CH CH 2 CH 3CH CH 2 S N 2 E2 E2 20% 80% (C H 3 ) 3CBr Et O - EtOH EtOH 25 25 (C H 3 ) 3COEt + (CH 3 ) 2C C H 2 (C H 3 ) 3COEt + (C H 3 ) 2C C H 2 81% 19% E2 7% 93% E2