Williamson

Williamson ether synthesis Alkyl halides react with sodium or potassium alkoxides or phenox-ides to give ethers. 

Neuhaus D and Williamson M 1989 The Nuclear Overhauser Effect in Structural and Conformational Analysis (New York VCH)... 

Figure Bl.13.6. The basic elements of a NOESY spectrum. (Reproduced by penuission of Wiley from Williamson M P 1996 Encyclopedia of Nuclear Magnetic Resonance ed D M Grant and R K Harris (Chichester Wiley) pp 3262-71).

Kent PRC, Flood R Q, Williamson A J, Needs R J, Foulkes W M C and Ra]agopal G 1999 Finite-size errors in quantum many-body simulations of extended systems Phys. Rev. B 59 1917-29... 

Wilcoxon J P, Williamson R L and Baughman R 1993 Optical properties of gold colloids formed in inverse micelles J. Chem. Phys. 98 9933... 

Sodium ethoxide gives an ether (Williamson s reaction). 

Williamson s lethod, more particularly lor hydroxy- and thloT (mercapto) compounds. The substance is treated either directly with sodium or (more usually) with a solution of sodium methoxide in methanol, to give the sodium derivative. The latter is then boiled with methvl iodide. 

Note that this is only a particular case of Williamson s general method for the preparation of ethers. 

Mixed ethers may be prepared by the interaction of an. alkyl halide and a sodium alkoxide (Williamson s synthesis), for example ... 

Williamson synthesis Wohl-Ziegler reaction Wolff rearrangement Wolff Kishner reduction Wurtz reaction Wurtz-Fittig reaction... 

Moodie, R. B., Schofield, K. Williamson, M. J. (1964). Nitro-Compounds, Proceedings of International Symposium, Warsaw (1963), p. 89. London Pergamon Press. 

Diazomethane alkylation of A-4-thiazoline-2-ones (36, 214) or the Williamson reaction of 2-halogenothiazoles (6. 287-300) provide good yields of 2-alkoxythiazole otherwise obtained by reaction between O-esters of monothiocarbamic acid with a-halocarbonyl compounds (see Chapter II). 

Methoxythiazole has been prepared by the Williamson reaction. The methoxy group exerts a bathochromic effect on the 233-nm band of the thiazole and shields both C-2H and C-5 H (0.67 and 0.89 ppm) (289). 

Alkoxythiazoles are prepared by heterocyclization (274, 462). The Williamson method using catalytic amounts of KI and cupric oxide is also possible (278. 288, 306). 5-Acetoxy-4-alkenylthiazoles are obtained by treatment of 242 with acetyl chloride and triethylamine or with acetic anhydride and pyridine (450). Similarly, the reaction of diphenylketene with 242 affords 5-acyloxy-4-alkenylthiazoles (243) (Scheme 120) (450). The readiness of these o-acetylations suggests that 4-alkylidene thiazoline-5-one might be in equilibrium with 4-alkenyl-5-hydroxythiazoles (450). 

The reaction is named for Alexander Williamson a British chemist who used it to prepare diethyl ether in 1850... 

A long standing method for the preparation of ethers is the Williamson ether synthesis Nucleophilic substitution of an alkyl halide by an alkoxide gives the carbon-oxygen bond of an ether... 

Preparation of ethers by the Williamson ether synthesis is most successful with methyl and primary alkyl halides... 

Write equations describing two different ways in which benzyl ethyl ether could be prepared by a Williamson ether synthesis J... 

Both reactants m the Williamson ether synthesis usually originate m alcohol pre cursors Sodium and potassium alkoxides are prepared by reaction of an alcohol with the appropriate metal and alkyl halides are most commonly made from alcohols by reaction with a hydrogen halide (Section 4 7) thionyl chloride (Section 4 13) or phosphorus tri bromide (Section 4 13) Alternatively alkyl p toluenesulfonates may be used m place of alkyl halides alkyl p toluenesulfonates are also prepared from alcohols as their imme diate precursors (Section 8 14)... 

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