{"id":40016,"date":"2025-06-27T12:25:20","date_gmt":"2025-06-27T12:25:20","guid":{"rendered":"https:\/\/gaviki.com\/blog\/?p=40016"},"modified":"2025-06-27T12:25:22","modified_gmt":"2025-06-27T12:25:22","slug":"propose-an-efficient-synthesis-for-each-of-the-following-transformation","status":"publish","type":"post","link":"https:\/\/gaviki.com\/blog\/propose-an-efficient-synthesis-for-each-of-the-following-transformation\/","title":{"rendered":"Propose an efficient synthesis for each of the following transformation"},"content":{"rendered":"\n

Propose an efficient synthesis for each of the following transformation: Br O (a) —–> OH (b) —–> Br (c) —–> Br (d) —<\/p>\n\n\n\n

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

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

Based on the transformations depicted in the image, here is a concise synthetic route for each:<\/p>\n\n\n\n

(a) Br \u2192 CO\u2082Me (methyl ester)<\/strong> Reaction Sequence:<\/strong><\/p>\n\n\n\n

    \n
  1. Mg, dry ether \u2192 Grignard reagent (R\u2013MgBr)<\/li>\n\n\n\n
  2. CO\u2082 (dry ice), then dilute HCl \u2192 Carboxylic acid<\/li>\n\n\n\n
  3. CH\u2083OH, H\u207a (acid-catalyzed esterification) \u2192 Methyl ester<\/li>\n<\/ol>\n\n\n\n

    (b) OH \u2192 C=O (ketone)<\/strong> Reaction Sequence:<\/strong><\/p>\n\n\n\n

      \n
    1. PCC (pyridinium chlorochromate) or DMP (Dess-Martin periodinane) in CH\u2082Cl\u2082 \u2192 Ketone<\/li>\n<\/ol>\n\n\n\n

      (c) Br \u2192 CONH\u2082 (amide)<\/strong> Reaction Sequence:<\/strong><\/p>\n\n\n\n

        \n
      1. NaCN, ethanol \u2192 Nitrile (R\u2013CN)<\/li>\n\n\n\n
      2. Acidic or basic hydrolysis (e.g., H\u2083O\u207a, heat) \u2192 Amide (CONH\u2082)<\/li>\n<\/ol>\n\n\n\n

        (d) Br (on primary carbon) \u2192 C=O (ketone)<\/strong> Reaction Sequence:<\/strong><\/p>\n\n\n\n

          \n
        1. NaCN \u2192 Nitrile<\/li>\n\n\n\n
        2. Grignard reagent (MeMgBr) \u2192 Imine intermediate<\/li>\n\n\n\n
        3. Acidic hydrolysis \u2192 Ketone (via ketimine)<\/li>\n<\/ol>\n\n\n\n

          Explanation<\/strong> Each route employs classic synthetic strategies aligned with the functional group interconversions in organic chemistry.<\/p>\n\n\n\n

          In (a), the bromine substituent on cyclohexane enables nucleophilic substitution to generate a Grignard reagent. Reaction with carbon dioxide introduces a carboxylic acid, which is then esterified under acidic methanol conditions to form the methyl ester.<\/p>\n\n\n\n

          For (b), secondary alcohols on a cyclohexane ring are cleanly oxidized to ketones using mild oxidizing agents like PCC or DMP. These reagents avoid overoxidation to carboxylic acids, preserving the desired ketone product.<\/p>\n\n\n\n

          The conversion in (c) begins with substitution of bromine by cyanide ion to introduce a nitrile group. Controlled hydrolysis under acidic or basic conditions then transforms the nitrile into an amide, a key functional group in biochemical systems and polymers.<\/p>\n\n\n\n

          In (d), starting from a bromoalkane, the route begins by converting the alkyl halide into a nitrile. Treatment with a Grignard reagent adds a methyl group, forming a ketimine intermediate. Hydrolysis in acidic conditions finalizes the transformation into a ketone.<\/p>\n\n\n\n

          Each strategy emphasizes selectivity, functional group compatibility, and accessible reagents, ensuring overall efficiency in synthesis.<\/p>\n\n\n\n

          \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

          Propose an efficient synthesis for each of the following transformation: Br O (a) —–> OH (b) —–> Br (c) —–> Br (d) — The Correct Answer and Explanation is: Based on the transformations depicted in the image, here is a concise synthetic route for each: (a) Br \u2192 CO\u2082Me (methyl ester) Reaction Sequence: (b) OH […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-40016","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/40016","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/comments?post=40016"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/40016\/revisions"}],"predecessor-version":[{"id":40019,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/40016\/revisions\/40019"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=40016"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=40016"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=40016"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}