Chemistry · Alcohols: Identification of primary, secondary and tertiary alcohols, mechanism of dehydration
alcohols preferably undergo dehydration in presence of
\( 1^{\circ} \) alcohols preferably undergo dehydration in presence of \( A l_{2} O_{3} \)
- A. \( E_{1} \)
- B. \( E_{2} \)
- C. \( S_{N} 1 \)
- D. \( S_{N} 2 \)
Step-by-step solution
Primary alcohols (1°) undergo dehydration via an E2 mechanism in the presence of Al2O3 because the carbocation intermediate required for E1 would be highly unstable. Al2O3 acts as a Lewis acid, promoting a concerted elimination where the C-O bond breaks and a C-H bond is removed simultaneously, favoring E2 over SN1/SN2.