{"id":185985,"date":"2025-01-23T20:00:13","date_gmt":"2025-01-23T20:00:13","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=185985"},"modified":"2025-01-23T20:00:15","modified_gmt":"2025-01-23T20:00:15","slug":"draw-the-expected-major-elimination-product-and-identify-the-mechanism","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/01\/23\/draw-the-expected-major-elimination-product-and-identify-the-mechanism\/","title":{"rendered":"Draw the expected major elimination product and identify the mechanism"},"content":{"rendered":"\n

Draw the expected major elimination product and identify the mechanism.<\/p>\n\n\n\n

The hint: The elimination product should be an alkene. Zaitsev\\’s rule says the more stable alkene will be formed. The presence of a strong or weak base determines E1 vs E2 mechanisms in tertiary alkyl halides.<\/p>\n\n\n\n

The correct answer and explanation is:<\/mark><\/strong><\/p>\n\n\n\n

The expected major elimination product and mechanism will depend on the alkyl halide and base involved. Let\u2019s break it down systematically.<\/p>\n\n\n\n

\n\n\n\n

Major Elimination Product<\/strong><\/h3>\n\n\n\n

The major elimination product is the more substituted alkene<\/strong>, following Zaitsev’s Rule<\/strong>, which states that elimination reactions typically favor the formation of the most thermodynamically stable (more substituted) alkene. For example, if the starting material is 2-bromo-2-methylbutane<\/strong>, the major product would be 2-methyl-2-butene<\/strong>, as it is more substituted than the alternative product, 2-methyl-1-butene<\/strong>.<\/p>\n\n\n\n

\n\n\n\n

Mechanism: E1 vs. E2<\/strong><\/h3>\n\n\n\n

The elimination mechanism depends on two main factors:<\/p>\n\n\n\n

    \n
  1. The nature of the substrate (e.g., tertiary, secondary, or primary alkyl halide).<\/li>\n\n\n\n
  2. The strength of the base used.<\/li>\n\n\n\n
  3. E1 Mechanism<\/strong>:\n
      \n
    • Occurs with tertiary alkyl halides<\/strong> or substrates that can form a stable carbocation.<\/li>\n\n\n\n
    • Favored in the presence of a weak base<\/strong> (e.g., water or ethanol).<\/li>\n\n\n\n
    • It proceeds in two steps:\n
        \n
      • Step 1: The leaving group (e.g., Br\u207b) departs, forming a carbocation.<\/li>\n\n\n\n
      • Step 2: A proton from a \u03b2-hydrogen is removed by the base, forming the alkene.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
      • Example: 2-bromo-2-methylpropane<\/strong> in ethanol produces 2-methylpropene<\/strong> via the E1 mechanism.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
      • E2 Mechanism<\/strong>:\n
          \n
        • Favored by a strong, bulky base<\/strong> (e.g., NaOH, NaOEt, or t-BuOK).<\/li>\n\n\n\n
        • Occurs in one concerted step: The base abstracts a \u03b2-hydrogen while the leaving group departs.<\/li>\n\n\n\n
        • Example: When 2-bromo-2-methylbutane<\/strong> reacts with NaOEt, the product is 2-methyl-2-butene<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n
          \n\n\n\n

          Conclusion<\/strong><\/h3>\n\n\n\n

          For a tertiary alkyl halide, if a strong base is used, the reaction will proceed via the E2 mechanism<\/strong> and give the Zaitsev product<\/strong> as the major alkene. Conversely, a weak base will favor the E1 mechanism<\/strong>, also leading to the Zaitsev product. The stereochemistry of the product depends on the specific mechanism.<\/p>\n","protected":false},"excerpt":{"rendered":"

          Draw the expected major elimination product and identify the mechanism. The hint: The elimination product should be an alkene. Zaitsev\\’s rule says the more stable alkene will be formed. The presence of a strong or weak base determines E1 vs E2 mechanisms in tertiary alkyl halides. The correct answer and explanation is: The expected major […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-185985","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/185985","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=185985"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/185985\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=185985"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=185985"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=185985"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}