Question

Which of the following is the best reagent to convert cyclohexanol into cyclohexene?

• A. Conc. $HCl$
• B. Conc. $HBr$
• C. Conc. $H_3{PO}_4$
• D. Conc. $HCl$ with ${ZnCl}_2$

Answer 1

The correct option is C Conc. $H_3{PO}_4$

Conc. $H_3{PO}_4$ is a good dehydrating agent which converts an alcohal to an alkene while the other three reagents are nucleophiles which convert alcohals to alkyl halides.