{"id":46875,"date":"2023-08-27T12:05:43","date_gmt":"2023-08-27T06:20:43","guid":{"rendered":"https:\/\/thechemistrynotes.com\/?p=46875"},"modified":"2023-08-27T12:05:46","modified_gmt":"2023-08-27T06:20:46","slug":"wittig-reaction-mechanism-applications","status":"publish","type":"post","link":"https:\/\/thechemistrynotes.com\/wittig-reaction-mechanism-applications\/","title":{"rendered":"Wittig\u00a0Reaction: Mechanism, Applications, Limitations"},"content":{"rendered":"\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"536\" src=\"https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reaction-1024x536.jpg\" alt=\"Wittig reaction \" class=\"wp-image-46888\" srcset=\"https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reaction-1024x536.jpg 1024w, https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reaction-300x157.jpg 300w, https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reaction-768x402.jpg 768w, https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reaction.jpg 1205w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>Wittig&nbsp;reaction facilitates the formation of an <a href=\"https:\/\/thechemistrynotes.com\/alkenes\/\">alkene <\/a>by reacting an aldehyde or ketone with the ylide produced by a phosphonium salt. The reactivity of the ylide affects the geometry of the resultant alkene. Georg Wittig invented the Wittig reaction in 1954, for which he received the Nobel Prize in Chemistry 25 years later.&nbsp; It is also known as Wittig olefination.<\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_65 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title \" >Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #0a0a0a;color:#0a0a0a\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #0a0a0a;color:#0a0a0a\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/thechemistrynotes.com\/wittig-reaction-mechanism-applications\/#what-is-wittigs-reaction\" title=\"What is Wittig&#8217;s&nbsp;reaction?\">What is Wittig&#8217;s&nbsp;reaction?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/thechemistrynotes.com\/wittig-reaction-mechanism-applications\/#mechanism-of-wittig-reaction\" title=\"Mechanism of Wittig reaction\">Mechanism of Wittig reaction<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/thechemistrynotes.com\/wittig-reaction-mechanism-applications\/#preparation-of-wittig-reagent\" title=\"Preparation of Wittig reagent\">Preparation of Wittig reagent<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/thechemistrynotes.com\/wittig-reaction-mechanism-applications\/#applications-of-wittig-reaction\" title=\"Applications of Wittig reaction\">Applications of Wittig reaction<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/thechemistrynotes.com\/wittig-reaction-mechanism-applications\/#limitations-of-wittig-reaction\" title=\"Limitations of Wittig&nbsp;reaction\">Limitations of Wittig&nbsp;reaction<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/thechemistrynotes.com\/wittig-reaction-mechanism-applications\/#references\" title=\"References\">References<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"what-is-wittigs-reaction\"><\/span><strong>What is Wittig&#8217;s&nbsp;reaction?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Witting reaction is a chemical process that produces alkene from aldehyde or ketone. The Wittig reaction is a crucial step in the synthesis of alkenes. The double bond occurs exactly where the original aldehyde or ketone was. Ylides are neutral molecules with +ve and -ve centers on adjacent atoms linked by a \u03c3&nbsp;bond. Triphenylphosphonium, generally known as the Wittig reagent, is the ylide that was utilized in this reaction.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"995\" height=\"193\" src=\"https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/image-165.png\" alt=\"Wittig reaction \" class=\"wp-image-46878\" srcset=\"https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/image-165.png 995w, https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/image-165-300x58.png 300w, https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/image-165-768x149.png 768w\" sizes=\"(max-width: 995px) 100vw, 995px\" \/><\/figure>\n\n\n\n<p>Wittig olefination stereoselectivity is complicated, but it can be generalized to ylide stability. Stabilized phosphoryl anions produce E-alkenes, whereas non-stabilized anions produce predominantly Z-alkenes. E-alkenes can be obtained from benzylic ylides, which are somewhat stabilized.&nbsp;One possible reason for this selectivity is that if the ylide is stable, the oxaphosphetane or betaine production is reversible, and thus only the faster of the two eliminations can occur to yield the trans isomer.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"mechanism-of-wittig-reaction\"><\/span><strong>Mechanism of Wittig reaction<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Step I: The ylide attacks the aldehyde, producing betaine,<\/p>\n\n\n\n<p>Step II: The betaine&nbsp;cyclizes to generate a stable oxaphosphetane.<\/p>\n\n\n\n<p>Step III: The oxaphosphetane collapses to form the product.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"623\" src=\"https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reaction-1024x623.png\" alt=\"Wittig reaction \" class=\"wp-image-46876\" srcset=\"https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reaction-1024x623.png 1024w, https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reaction-300x183.png 300w, https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reaction-768x468.png 768w, https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reaction-1536x935.png 1536w, https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reaction.png 1853w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div>\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"preparation-of-wittig-reagent\"><\/span><strong>Preparation of Wittig reagent<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Triphenyl triphenylphosphine (Ph<sub>3<\/sub>P) and an alkyl halide are used to make the Wittig reagent in two phases. First, the Ph<sub>3<\/sub>P functions as a nucleophile in the SN<sub>2<\/sub> reaction, replacing the halide to produce a phosphonium salt.<\/p>\n\n\n\n<p>The carbon in the phosphonium salt is linked to a positively charged phosphorus capable of accepting another pair of electrons (P can be greater than the octet). This allows a strong base, such as an organolithium reagent, to remove the hydrogen next to the phosphorous, creating the desired ylid.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"465\" src=\"https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reagent-1024x465.png\" alt=\"Wittig reagent\" class=\"wp-image-46877\" srcset=\"https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reagent-1024x465.png 1024w, https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reagent-300x136.png 300w, https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reagent-768x349.png 768w, https:\/\/thechemistrynotes.com\/wp-content\/uploads\/2023\/08\/Wittig-reagent.png 1536w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div>\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"applications-of-wittig-reaction\"><\/span><strong>Applications of Wittig reaction<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul>\n<li>The witting reaction is the most general process for alkene synthesis. Due to the reaction&#8217;s selectivity and versatility under mild conditions, it is still a topic worth studying today.<\/li>\n\n\n\n<li>The Wittig reaction is a vital tool in organic chemistry that is utilized not only in laboratories but also in the&nbsp;industry to synthesize -carotene and vitamin A derivatives.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"limitations-of-wittig-reaction\"><\/span><strong>Limitations of Wittig&nbsp;reaction<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul>\n<li>Aldehydes are easily capable of polymerization, oxidation, and decomposition.<\/li>\n\n\n\n<li>Both the E and Z double-bond&nbsp;isomers can be obtained.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"references\"><\/span><strong>References<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul>\n<li>Morrison R. T. &amp; Boyd R. N. (1983).&nbsp;<em>Organic chemistry<\/em>&nbsp;(4th ed.). Allyn and Bacon.<\/li>\n\n\n\n<li>Smith M. &amp; March J. (2001).&nbsp;<em>March\u2019s Advanced Organic Chemistry: Reactions Mechanisms and Structure<\/em>&nbsp;(5th ed.). Wiley.<\/li>\n\n\n\n<li>Ghosh, S.K.,&nbsp;<em>Advanced General Organic Chemistry<\/em>, Second Edition, New Central Book Agency Pvt. Ltd., Kolkatta, 2007.<\/li>\n\n\n\n<li>Bahl, B.S., A., Advanced Organic Chemistry, S. Chand and Company Ltd, New Delhi, 1992. production of polyesters, polyurethanes, and alkaline resins.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Wittig&nbsp;reaction facilitates the formation of an alkene by reacting an aldehyde or ketone with the ylide produced by a phosphonium salt. The reactivity of the ylide affects the geometry of &#8230; <a title=\"Wittig\u00a0Reaction: Mechanism, Applications, Limitations\" class=\"read-more\" href=\"https:\/\/thechemistrynotes.com\/wittig-reaction-mechanism-applications\/\" aria-label=\"Read more about Wittig\u00a0Reaction: Mechanism, Applications, Limitations\">Read more<\/a><\/p>\n","protected":false},"author":4,"featured_media":46888,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[21],"tags":[2776,2777,2775,2774],"_links":{"self":[{"href":"https:\/\/thechemistrynotes.com\/wp-json\/wp\/v2\/posts\/46875"}],"collection":[{"href":"https:\/\/thechemistrynotes.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/thechemistrynotes.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/thechemistrynotes.com\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/thechemistrynotes.com\/wp-json\/wp\/v2\/comments?post=46875"}],"version-history":[{"count":3,"href":"https:\/\/thechemistrynotes.com\/wp-json\/wp\/v2\/posts\/46875\/revisions"}],"predecessor-version":[{"id":46889,"href":"https:\/\/thechemistrynotes.com\/wp-json\/wp\/v2\/posts\/46875\/revisions\/46889"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/thechemistrynotes.com\/wp-json\/wp\/v2\/media\/46888"}],"wp:attachment":[{"href":"https:\/\/thechemistrynotes.com\/wp-json\/wp\/v2\/media?parent=46875"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/thechemistrynotes.com\/wp-json\/wp\/v2\/categories?post=46875"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/thechemistrynotes.com\/wp-json\/wp\/v2\/tags?post=46875"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}