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The Williamson ether synthesis is an organic reaction, forming an ether from an organohalide and a deprotonated alcohol . This reaction was developed by Alexander Williamson in 1850. [ 2 ] Typically it involves the reaction of an alkoxide ion with a primary alkyl halide via an S N 2 reaction .
Alexander Williamson. Williamson is credited for his research on the formation of unsymmetrical ethers by the interaction of an alkoxide with a haloalkane, known as the Williamson ether synthesis. He regarded ethers and alcohols as substances analogous to and built up on the same type as water, and he further introduced the water-type as a ...
18-Crown-6 can be synthesized by the Williamson ether synthesis using potassium ion as the template cation. Structure of nickel-aquo nitrate complex of the ligand derived from the templated trimerization of 2-aminobenzaldehyde. [5] The phosphorus analogue of an aza crown can be prepared by a template reaction. [6]
Williamson ether synthesis; R−Br + OR' − → R−OR' + Br − (S N 2) The Wenker synthesis, a ring-closing reaction of aminoalcohols. The Finkelstein reaction, a halide exchange reaction. Phosphorus nucleophiles appear in the Perkow reaction and the Michaelis–Arbuzov reaction. The Kolbe nitrile synthesis, the reaction of alkyl halides ...
Usually phenol ethers are synthesized through the condensation of phenol and an organic alcohol; however, other known reactions regarding the synthesis of ethers can be applied to phenol ethers as well. Anisole (C 6 H 5 OCH 3) is the simplest phenol ether, and is a versatile precursor for perfumes and pharmaceuticals. [1]
Sodium phenoxide reacts with alkylating agents to afford alkyl phenyl ethers: [2] NaOC 6 H 5 + RBr → ROC 6 H 5 + NaBr. The conversion is an extension of the Williamson ether synthesis. With acylating agents, one obtains phenyl esters: [citation needed] NaOC 6 H 5 + RC(O)Cl → RCO 2 C 6 H 5 + NaCl
In figure 11 below the rate determining step for Williamson ether synthesis is shown. [9] [10] The starting material is methyl chloride and an ethoxide ion which has a localized negative charge meaning it is more stable in polar solvents. The figure shows a transition state structure as the methyl chloride undergoes nucleophilic attack.
As a consequence, alkoxides (and hydroxide) are powerful bases and nucleophiles (e.g., for the Williamson ether synthesis) in this solvent. In particular, RO − or HO − in DMSO can be used to generate significant equilibrium concentrations of acetylide ions through the deprotonation of alkynes (see Favorskii reaction). [36] [37]