引用第1353樓yanyan於2009-04-06 18:42發表的“”:
BBC?
not sure
我考埋bio先再溫org chem 了 [表情]
應該係BBD
<-- 我估=-=
我係咁諗的:
第一題,
C,D 個benzene ring fake 人的,冇mesomeric effect, just regard them as primary alkoxide ion
第2題,
reactivity 用 steric effect,個basicity of leaving group 黎比較
A<=>B, A 個steric hindrance/ bascity of leaving group 高過B
C,D同B比較,佢個leaving group 個bascity 應該高過ethanoate ion, 即刻佢有個benzene ring 玩resonance, 應該冇咁effective, 同埋steric hindrance due to it 都好大下
第3題,
C 有個benzene ring
,stablise 左了
A,B 其實都係conjugate system 黎的.. delocalisation exists..
thus, 又係會stablise 左個tri ene