Fundamentals of Organic ChemistryChemistryAlcohols Phenols and Ethers
Consider the following three proposed syntheses for phenyl propyl ether: (i) (ii) (iii) Which of the above syntheses is/are viable?
Options
- A(i) and (iii) only
- B(ii) and (iii) only
- C(i) only
- D(iii) only
Correct answer
C. (i) only
Step-by-step solution
Synthesis (i) involves the deprotonation of phenol by KNH ₂ to form potassium phenoxide. The phenoxide ion acts as a good nucleophile and reacts with 1-bromopropane (a primary alkyl halide) via an S _ N 2 mechanism to successfully form phenyl propyl ether. This is a standard and viable Williamson ether synthesis. Synthesis (ii) attempts to form sodium propoxide using NaOH , but the equilibrium does not favor alkoxide formation. More importantly, the second step requires the nucleophilic substitution of bromobenzene