Chemistry Alkyl Halides BUMHS 2024
PMDC Verified Question 8 of 13
The procedure for the preparation of ethers in which an alcohol is first allowed to react with metallic sodium is called:
A
Tollen's synthesis
B
Fehling's synthesis
C
Williamson's synthesis
D
Grignard's synthesis
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option C: Williamson's synthesis
Concept:

The standard laboratory method for creating asymmetrical or symmetrical ethers involves an \( S_N2 \) reaction between an alkoxide ion and an alkyl halide.

Solution:

  • Step 1: An alcohol (\( R-OH \)) is reacted with an active metal like sodium (\( Na \)) to produce sodium alkoxide (\( R-O^-Na^+ \)), releasing hydrogen gas.
  • Step 2: This strong nucleophile (alkoxide) is then reacted with a primary alkyl halide (\( R'-X \)).
  • The alkoxide attacks the alkyl halide, displacing the halogen to form an ether (\( R-O-R' \)).
  • This two-step protocol was developed by Alexander Williamson and is universally known as the Williamson ether synthesis.


Why other options are incorrect:

  • Options A & B: Tollen's and Fehling's reagents are used to test for the presence of aldehydes.
  • Option D: Grignard synthesis uses magnesium to create organometallic reagents for carbon-carbon bond formation.

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