Ferf-Butyl ethers halides

Hydroxy compounds and ferf-butyl ethers from halides... 

Methanol is a common feedstock considered as a building block in the chemical industry because of its versatility in the synthesis of several important chemicals such as chloromethane, acetic acid, methyl ferf-butyl ether (MTBE), alkyl halides, and formaldehyde [202, 203]. Methanol can be converted into DME which is... 

Treatment of A and B with hydrogen over a nickel catalyst results in quantitative conversion of each compound to ferf-butyl alcohol. A reacts with acyl halides and anhydrides, whereas B is unaffected by these reagents. Treatment of 1 mole of A with excess methylmagnesium iodide in diethyl ether solution produces 1 mole of methane and 1 moie each of ferf-butyl alcohol and methanol. One mole of B with excess methylmagnesium iodide produces 1 mole of 2-methoxy-2-methylpropene and 1 mole of ferf-butyl alcohol. 

If, instead, you used a ferf-butyl halide and ethoxide ion, you would not obtain any ether because the reaction of a tertiary alkyl halide under Sn2/E2 conditions forms only the elimination product. 

Mechanistically, the Williamson synthesis is simply an 8 2 displacement of halide ion by an alkoxide ion nucleophile. The Williamson synthe sis is thus subject to all the usual constraints on 8 2 reactions discusser in Section 11.5. Primary halides and tosylates work best because competi tive E2 elimination of HX can occur with more hindered substrates. Unsym-metrical ethers should therefore be synthesized by reaction between thi more hindered alkoxide partner and less hindered halide partner rathe than vice versa. For example, tert-butyl methyl ether, a substance used c an octane booster in gasoline, is best prepared by reaction of ferf-butoxidc ion with iodomethane rather than by reaction of methoxide ion with 2-chloro-2-methylpropane. 

If, however, you want to synthesize tert-butyl ethyl ether, the starting materials must be an ethyl halide and ferf-butoxide ion. If you tried to use a tert-butyl halide and ethoxide ion as reactants, you would obtain the elimination product and little or no ether because the reaction of a tertiary alkyl halide under Sn2/E2 conditions forms primarily the elimination product. So, in carrying out a Williamson ether synthesis, the... 

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