E2 Elimination (Dehydrohalogenation)

C₂H₅Br + KOH → C₂H₄ + KBr + H₂O

نظرة عامة

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.

المشاركون

الدور	المادة	المعامل	الحالة
متفاعل	Potassium Hydroxide KOH	1	(aq)
منتج	Ethylene C₂H₄	1	(g)
منتج	Water H₂O	1	(l)

مثال من الحياة اليومية

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

الأهمية الصناعية

Dehydrohalogenation is used in the manufacture of vinyl chloride (from ethylene dichloride) and in producing various alkene monomers.

الخصائص

النوع: Organic
قابل للعكس: لا
الطاقة: طارد للحرارة
ΔH: -50,0 kJ/mol

التفاعلات ذات الصلة

Swern Oxidation Oxidation of Secondary Alcohol to Ketone Claisen Condensation (Ethyl Acetate) Kolbe Electrolysis Baeyer-Villiger Oxidation Beckmann Rearrangement (Cyclohexanone Oxime) Catalytic Hydrogenation of Ethylene Condensation Polymerization (Nylon 6,6) Cope Rearrangement Epoxidation of Alkenes (mCPBA)

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.