# clemmensen reduction acid sensitive

Clemmensen reduction is a chemical reaction described as a reduction of ketones (or aldehydes) to alkanes using zinc amalgam and concentrated hydrochloric acid. Then apply the same reasoning to 'halogens', as you call them, in basic medium, and you will have your answer. Author has 1.2k answers and 632.7k answer views The key difference between the reactivity of carboxylic acids and ketones/aldehydes in the Clemmensen reduction is due to the formation of a zinc salt of carboxylic acids. Determining CRS from given point coordinate set. We need to use a catalyst for this reaction; it is amalgamated zinc (mercury alloyed with zinc ) with hydrochloric acid. The oxygen atom is lost in the form of one molecule of water. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. * The Clemmensen reduction is complementary to Wolff-Kishner reduction, which may be used to reduce acid sensitive compounds. If you choose to do an acid hydrolysis of an ester, be aware of the lability of acetals under these conditions. Is it ok to place 220V AC traces on my Arduino PCB? Clemmensen’s reduction is not suitable for substances sensitive to acids. Asking for help, clarification, or responding to other answers. What framework or methodology would you recommend for a Data Science team? A proton can attack an OH group so that the resulting group can leave as H2O. The hydrazine will quite happily displace the halogen, indeed OH- can displace or eliminate the halogen too. Why are the divisions of the Bible called "verses"? Acid sensitive substrates should be reacted in the Wolff-Kishner reduction, which utilizes strongly basic conditions; a further, milder method is the Mozingo reduction. site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. The mechanism of action is not exactly clear. This seems incorrect to me as Halogens are clearly not in need of electrons. What if you are a tertiary alcohol under Clemmensen conditions? Clemmensen reduction is an organic chemical reaction in which we convert a ketone or aldehydes into an alkane. The substrate must be unreactive to the strongly acidic conditions of the Clemmensen reduction. The substrate should not be acid sensitive, if the substrate is acid sensitive then reduction is carried out by Wolff-Kishner reduction. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. * There is a net flow of electrons from zinc to the carbonyl compound. The Clemmensen reduction is named after a Danish chemist, Erik Christian Clemmensen. In the second case, both the Halogen and attacking base have a surplus of electrons, so why would there a reaction? There are two proposed mechanisms i.e. Making statements based on opinion; back them up with references or personal experience. I can see why alcohols would be acid-sensitive but why would Halogens be base-sensitive? The reduction consists in refluxing the carbonyl compounds with amalgamated zinc and excess of concentrated hydrochloric acid. This happens because the proton requires electrons and the alcohol has extra lone pairs of electrons. Thanks for contributing an answer to Chemistry Stack Exchange! What's the finest readily-available way to write on paper? Why did they change the registry number of USS Discovery? Clemmensen Reduction Reaction. Why do electron donating groups decrease the acidity of aromatic carboxylic acids? The term "sensitive" means some group also reacts under conditions designed for some other group. MAINTENANCE WARNING: Possible downtime early morning Dec 2/4/9 UTC (8:30PM…, “Question closed” notifications experiment results and graduation. The reduction of carbonyl groups of aldehydes and ketones to methylene groups with amalgamated zinc and concentrated hydrochloric acid is known as Clemmensen reduction. MathJax reference. If you want to effect a Wolff-Kishner, be aware of E2 elimination elsewhere in the molecule. Why do you think alcohols are acid-sensitive? MECHANISM OF CLEMMENSEN REDUCTION * The Clemmensen reduction occurs over the surface of zinc catalyst. The Clemmensen reduction is a reaction that is used to reduce aldehydes or ketones to alkanes using hydrochloric acid and zinc amalgam. Chemistry Stack Exchange is a question and answer site for scientists, academics, teachers, and students in the field of chemistry. My textbook says that Clemmensen Reduction cannot take place in the presence of an acid-sensitive group and the Wolf Kishner reaction won't happen in the presence of a base sensitive group, citing $\ce{-OH}$ (alcohol) and $\ce{-X}$ (halogens) as respective examples. However, I read from somewhere else that: Acid sensitive groups are groups which are electron donors or have spare electrons, like $\ce{NH3}$. By which I mean, what is going to happen to an alcohol in acidic medium? Why does this review of Star Trek IV include an image of Link from Legend of Zelda? Why do the mountain people make roughly spherical houses? Use MathJax to format equations. Reduction of 1,4-benzoquinone in the synthesis of 1,5-diazocane. Group 15… Lewis Acid, Lewis Base or Not At All? Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. To learn more, see our tips on writing great answers. It only takes a minute to sign up. rev 2020.11.24.38066, The best answers are voted up and rise to the top, Chemistry Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us. The intrinsic electron-withdrawing nature of alkyl groups, Crank is slipping relative to large chainring but not the small one. However, I read from somewhere else that: carbanionic mechanism where the attack of Zn is involved and carbenoid mechanism where Zn act as a surface to perform reaction and it is a radical process. The necessary secondary characteristics of a humanoid, sequentially hermaphroditic race, Forecasting Prices vs Returns by Deep Learning. The probable mechanism is shown below. What could Trump hope to gain from a *second* Georgia "recount"? The reduction is useful especially for ketones containing phenolic or carboxylic groups which remain … What's the current state of LaTeX3 (2020)? My textbook says that Clemmensen Reduction cannot take place in the presence of an acid-sensitive group and the Wolf Kishner reaction won't happen in the presence of a base sensitive group, citing − O H (alcohol) and − X (halogens) as respective examples. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Scalability problem: is the end of Bitcoin near? If the reactant molecule incorporates an acid-sensitive group, such as the hydroxyl group (-OH), the hydrogen ions will attack them instead of attacking the carbonyl group, resulting in the failure of the reaction.