{"id":186469,"date":"2025-01-25T08:04:42","date_gmt":"2025-01-25T08:04:42","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=186469"},"modified":"2025-01-25T08:04:44","modified_gmt":"2025-01-25T08:04:44","slug":"draw-the-structures-of-the-starting-materials-needed-to-make-2-methylhept-3-yne-in-the-spaces-provided","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/01\/25\/draw-the-structures-of-the-starting-materials-needed-to-make-2-methylhept-3-yne-in-the-spaces-provided\/","title":{"rendered":"Draw the structures of the starting materials needed to make 2-methylhept-3-yne in the spaces provided"},"content":{"rendered":"\n

Draw the structures of the starting materials needed to make 2-methylhept-3-yne in the spaces provided. The starting materials may be any bromoalkane having five carbons or fewer.<\/p>\n\n\n\n

a) The starting hydrocarbon must be a bromoalkane with five carbons or fewer.<\/p>\n\n\n\n

b) The hydrocarbon must be a bromoalkane with five carbons or fewer.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

The Correct Answer and Explanation is :<\/strong><\/mark><\/p>\n\n\n\n

To prepare 2-methylhept-3-yne, you will need to use two key reactions, involving a bromoalkane with five carbons or fewer as starting materials.<\/p>\n\n\n\n

Step-by-Step Explanation:<\/strong><\/h3>\n\n\n\n
    \n
  1. Starting Material Selection:<\/strong> The first step is choosing a bromoalkane with five carbons or fewer. Based on the structure of 2-methylhept-3-yne (which has a triple bond at the 3-position and a methyl group at the 2-position), we need to construct a chain of seven carbons with these substituents. The ideal starting bromoalkane is 1-bromo-3-methylbutane<\/strong> (C5H11Br). This compound is a bromoalkane with five carbon atoms, which fits the requirement.<\/li>\n\n\n\n
  2. Elimination Reaction:<\/strong> The synthesis proceeds by an elimination reaction<\/strong>. In the presence of a strong base (like potassium hydroxide, KOH), 1-bromo-3-methylbutane undergoes a dehydrobromination reaction. The base abstracts a hydrogen atom from the \u03b2-carbon (the second carbon from the bromine), leading to the formation of a double bond<\/strong> between the second and third carbons.<\/li>\n\n\n\n
  3. Formation of 2-methylpent-2-ene:<\/strong> After this elimination, the product formed is 2-methylpent-2-ene<\/strong>, which has a double bond between carbons 2 and 3 and a methyl group attached to carbon 2.<\/li>\n\n\n\n
  4. Alkyne Formation:<\/strong> Next, an additional halogenation and elimination reaction<\/strong> are required to convert the alkene into an alkyne. React the 2-methylpent-2-ene<\/strong> with a halogen, like bromine, in the presence of a strong base (for example, sodium amide, NaNH2). This will result in a bromine elimination reaction<\/strong>, where a second hydrogen atom is abstracted from the \u03b2-carbon, resulting in a triple bond<\/strong> between carbons 2 and 3.<\/li>\n\n\n\n
  5. Product Formation:<\/strong> The final product is 2-methylhept-3-yne<\/strong>, which contains a triple bond at the 3-position and a methyl group at the 2-position.<\/li>\n<\/ol>\n\n\n\n

    Structure of 1-bromo-3-methylbutane:<\/strong><\/h3>\n\n\n\n
      \n
    • The structure of 1-bromo-3-methylbutane is: CH3-CH2-CH(Br)-CH3<\/code><\/li>\n<\/ul>\n\n\n\n

      In this structure, the bromo group is on carbon 1, with a methyl group on carbon 3.<\/p>\n\n\n\n

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

      Thus, 1-bromo-3-methylbutane<\/strong> is the starting material needed to synthesize 2-methylhept-3-yne. Through elimination reactions, it undergoes a transformation into 2-methylpent-2-ene, which then undergoes another elimination to form the desired alkyne.<\/p>\n","protected":false},"excerpt":{"rendered":"

      Draw the structures of the starting materials needed to make 2-methylhept-3-yne in the spaces provided. The starting materials may be any bromoalkane having five carbons or fewer. a) The starting hydrocarbon must be a bromoalkane with five carbons or fewer. b) The hydrocarbon must be a bromoalkane with five carbons or fewer. The Correct Answer […]<\/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-186469","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/186469","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=186469"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/186469\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=186469"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=186469"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=186469"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}