E2 Elimination (Dehydrohalogenation)

C2H5Br + KOH → C2H4 + KBr + H2O

개요

Strong base (KOH in ethanol) removes a beta-hydrogen and the halide leaves simultaneously in a concerted E2 elimination to form an alkene. The H and Br must be anti-periplanar (180 degrees) for the elimination to proceed. E2 competes with SN2, with bulky bases and secondary/tertiary substrates favoring elimination.

참여 물질

역할 물질 계수 상태
반응물 Potassium Hydroxide KOH 1 (aq)
생성물 Ethylene C₂H₄ 1 (g)
생성물 Water H₂O 1 (l)

일상 속 예시

E2 elimination is used to prepare alkenes from easily available alkyl halides and is key to understanding organic reaction selectivity.

산업적 중요성

알켄 합성의 주요 방법으로, 제약 및 정밀화학 산업에서 불포화 화합물 제조에 활용됩니다. 입체화학적 선택성(안티 입체특이성)을 이용한 특정 기하 이성질체 합성에 중요합니다.

성질

유형
Organic
가역 반응
아니오
에너지
발열
ΔH
-50.0 kJ/mol

관련 반응

Epoxidation of Alkenes (mCPBA) Swern Oxidation Oxidation of Secondary Alcohol to Ketone Claisen Condensation (Ethyl Acetate) Aldol Condensation of Acetaldehyde Kolbe Electrolysis Baeyer-Villiger Oxidation Beckmann Rearrangement (Cyclohexanone Oxime) Catalytic Hydrogenation of Ethylene Dehydration of Ethanol

Frequently Asked Questions

What is the equation for E2 Elimination (Dehydrohalogenation)?
The balanced equation is: C₂H₅Br + KOH → C₂H₄ + KBr + H₂O.
What type of reaction is E2 Elimination (Dehydrohalogenation)?
E2 Elimination (Dehydrohalogenation) is a organic reaction.
Is E2 Elimination (Dehydrohalogenation) exothermic or endothermic?
E2 Elimination (Dehydrohalogenation) is exothermic (releases energy). The enthalpy change (ΔH) is -50.0 kJ/mol.