10.19 Predict all the alkenes that would be formed by dehydrohalogenation of the following halides with sodium ethoxide in ethanol and identify the major alkene: (i) 1-Bromo-1-methylcyclohexane (ii) 2-Chloro-2-methylbutane (iii) 2,2,3-Trimethyl-3-bromopentane

<p>Carbon due to its chemical property of catenation, &lt;a href="https://www.shiksha.com/preparation/chemistry-organic-chemistry-tetravalence-of-carbon-shapes-of-organic-compounds-5630-tp"&gt;tetravalency&lt;/a&gt; and the ability to form stable covalent bonds form hydrocarbon and halo-alkanes easily.</p><p>The process of removal of hydrogen and halogen from adjacent carbon atoms of haloalkens is called dehydrohalogenation. <strong>NaOEt ( </strong>Sodium ethoxide) used in Dehydrohalogenation. &nbsp;It is a strong base and helps remove a β-hydrogen from the haloalkane.</p><p>The chemical reaction for</p><h3><strong>Reaction:</strong></h3><p>R–CH2 –CHX–R′+NaOEt &nbsp;&nbsp;<strong><u>ethanol</u> </strong>&gt; R–CH=CHR’+NaX+EtOH</p><p>(i) 1-Bromo-1-methylcyclohexane:&nbsp;</p><p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Br<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; |<br>&nbsp;CH3–C1–cyclohexane&nbsp; + NaOEt/EtOH → CH3–C=cyclohexane (double bond at C1-C2) + NaBr + EtOH</p><p>Major Product: 1-Methylcyclohexene</p><p>&nbsp;</p><p><strong>(ii) 2-Chloro-2-methylbutane</strong></p><p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CH3<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; |<br>&nbsp;CH3–C–CH2–CH3&nbsp;&nbsp; + NaOEt/EtOH → CH3–C=CH–CH3 + NaCl + EtOH<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; |&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Cl&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CH3</p><p>Major Product: 2-Methyl-2-butene (major), 2-Methyl-1-butene (minor)</p><p>&nbsp;</p><p><strong>(iii) 2,2,3-Trimethyl-3-bromopentane</strong></p><p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CH3&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CH3<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; |&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; |<br>&nbsp;CH3–C–C–CH2–CH3&nbsp; + NaOEt/EtOH → CH3–C=C–CH2–CH3 + NaBr + EtOH<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; |&nbsp;&nbsp; |&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CH3&nbsp; Br&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CH3</p><p>Major Product: 2,2,3-Trimethyl-2-pentene</p><div><div><span data-teams="true">Follow along &lt;a title="https://www.shiksha.com/preparation/chemistry-ncert-solutions-class-11th-ns" href="https://www.shiksha.com/preparation/chemistry-ncert-solutions-class-11th-ns" target="_blank" rel="noreferrer noopener" aria-label="Link NCERT Chemistry 11th"&gt;NCERT Solutions for Chemistry 11th&lt;/a&gt;</span></div></div>

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