{"id":204203,"date":"2025-03-21T15:54:14","date_gmt":"2025-03-21T15:54:14","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=204203"},"modified":"2025-03-21T15:54:17","modified_gmt":"2025-03-21T15:54:17","slug":"beginning-with-sodium-acetylide-nacch-propose-a-three-step-synthesis-of-hexanal","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/03\/21\/beginning-with-sodium-acetylide-nacch-propose-a-three-step-synthesis-of-hexanal\/","title":{"rendered":"Beginning with sodium acetylide (NaCCH), propose a three-step synthesis of hexanal"},"content":{"rendered":"\n

Beginning with sodium acetylide (NaCCH), propose a three-step synthesis of hexanal.<\/p>\n\n\n\n

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

To synthesize hexanal starting from sodium acetylide (NaCCH), a three-step synthesis could be designed as follows:<\/p>\n\n\n\n

Step 1: Addition of Sodium Acetylide to Formaldehyde<\/h3>\n\n\n\n

The first step involves the nucleophilic addition of sodium acetylide (NaCCH) to formaldehyde (CH\u2082O). Sodium acetylide is a strong nucleophile, with the acetylide ion (C\u2261C\u207b) attacking the electrophilic carbonyl carbon of formaldehyde.<\/p>\n\n\n\n

Reaction:<\/strong> NaCCH+CH2O\u2192CH3C(OH)CH2 \\text{NaCCH} + \\text{CH}_2\\text{O} \\rightarrow \\text{CH}_3\\text{C}(\\text{OH})\\text{C}H_2<\/p>\n\n\n\n

In this reaction, sodium acetylide reacts with formaldehyde to form 1-propynol (CH\u2083C(OH)CH\u2082), which is an alcohol with a terminal alkyne group.<\/p>\n\n\n\n

Step 2: Reduction of 1-Propynol to 1-Propanol<\/h3>\n\n\n\n

The second step involves the reduction of the alkyne in 1-propynol to a saturated alcohol. This can be achieved by catalytic hydrogenation or by using a reducing agent such as Lindlar\u2019s catalyst, which specifically reduces alkynes to cis-alkenes.<\/p>\n\n\n\n

Reaction:<\/strong> CH3C(OH)CH2\u2192H2Lindlar\u2019s catalystCH3CH2OH\\text{CH}_3\\text{C}(\\text{OH})\\text{C}H_2 \\xrightarrow[\\text{H}_2]{\\text{Lindlar’s catalyst}} \\text{CH}_3\\text{CH}_2\\text{OH}<\/p>\n\n\n\n

The reaction reduces the triple bond to a single bond, resulting in 1-propanol (CH\u2083CH\u2082OH), an alcohol.<\/p>\n\n\n\n

Step 3: Oxidation of 1-Propanol to Hexanal<\/h3>\n\n\n\n

In the final step, 1-propanol undergoes oxidation to form hexanal (C\u2086H\u2081\u2082O). This can be accomplished using an oxidizing agent like PCC (pyridinium chlorochromate) or any mild oxidizing agent that selectively oxidizes alcohols to aldehydes without further oxidation to acids.<\/p>\n\n\n\n

Reaction:<\/strong> CH3CH2OH\u2192PCCCH3CH2CH2CHO\\text{CH}_3\\text{CH}_2\\text{OH} \\xrightarrow{\\text{PCC}} \\text{CH}_3\\text{CH}_2\\text{CH}_2\\text{CHO}<\/p>\n\n\n\n

This oxidation reaction results in the formation of hexanal (CH\u2083CH\u2082CH\u2082CHO), which is an aldehyde.<\/p>\n\n\n\n

Explanation:<\/h3>\n\n\n\n

In this three-step synthesis:<\/p>\n\n\n\n

    \n
  1. Sodium acetylide acts as a nucleophile, attacking the carbonyl carbon of formaldehyde to form a 1-propynol intermediate.<\/li>\n\n\n\n
  2. The alkyne functional group in 1-propynol is reduced to a saturated alcohol, yielding 1-propanol.<\/li>\n\n\n\n
  3. Finally, the alcohol is oxidized to an aldehyde, yielding hexanal.<\/li>\n<\/ol>\n\n\n\n

    This synthesis route is efficient, utilizing relatively simple reagents and common reactions to achieve the desired product.<\/p>\n","protected":false},"excerpt":{"rendered":"

    Beginning with sodium acetylide (NaCCH), propose a three-step synthesis of hexanal. The correct answer and explanation is : To synthesize hexanal starting from sodium acetylide (NaCCH), a three-step synthesis could be designed as follows: Step 1: Addition of Sodium Acetylide to Formaldehyde The first step involves the nucleophilic addition of sodium acetylide (NaCCH) to formaldehyde […]<\/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-204203","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/204203","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=204203"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/204203\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=204203"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=204203"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=204203"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}