Wurtz reaction - wikipedia Wurtz reaction Wurtz reaction Named after Charles - Adolphe Wurtz Reaction type Coupling reaction Identifiers Organic Chemistry Portal wurtz - reaction RSC ontology ID RXNO : 0000074 The Wurtz reaction, named after Charles - Adolphe Wurtz, is a coupling reaction in organic chemistry, organometallic chemistry and recently inorganic main group polymers, whereby two alkyl halides are reacted with sodium metal in dry ether solution to form a higher alkane : 2R -- X + 2Na → R -- R + 2Na X Other metals have also been used to effect the Wurtz coupling, among them silver, zinc, iron, activated copper, indium and a mixture of manganese and copper chloride. The related reaction dealing with aryl halides is called the Wurtz - Fittig reaction. This can be explained by the formation of free radical intermediate and its subsequent disproportionation to give alkene. The Wurtz reaction occurs through a free radical mechanism. Contents 1 Mechanism 2 Examples and reaction conditions 3 Limitations 4 See also 5 References Mechanism The reaction consists of a halogen - metal exchange involving the radical species R ( in a similar fashion to the formation of a Grignard reagent ) with carbon -- carbon bond formation occurring in a nucleophilic substitution reaction. One electron from the metal is transferred to the halogen to produce a metal halide and an alkyl radical. R -- X + M → R + M X The alkyl radical then accepts an electron from another metal atom to form an alkyl anion. This intermediate has been isolated in several cases. R + M → R M The nucleophilic carbon of the alkyl anion then displaces the halide in an S 2 reaction, forming a new carbon - carbon covalent bond. R M + R -- X → R -- R + M X Examples and reaction conditions Due to several limitations this reaction is seldom used. For example, it is intolerant of a range of functional groups. Wurtz coupling is, however, useful in closing small, especially three - membered, rings. Bicyclobutane was prepared this way from 1 - bromo - 3 - chlorocyclobutane in 95 % yield. The reaction is conducted in refluxing dioxane, at which temperature, the sodium is liquid. This reaction has poor yield which is a consequence of multiple product formation. In the case of ( 1, 3 ), ( 1, 4 ), ( 1, 5 ), ( 1, 6 ) dihalides, it leads to formation of cyclic products. In vicinal dihalides, it forms alkenes whereas in geminal dihalides, it forms alkynes. Limitations The Wurtz reaction is limited to the synthesis of symmetric alkanes. If two dissimilar alkyl halides are taken as reactants, then the product is a mixture of alkanes that is often difficult to separate by fractional distillation as the differences between the boiling points of the products is typically very low. Also, since the reaction involves free radical species, a side reaction occurs to produce an alkene. This side - reaction becomes more significant when the alkyl halides are bulky at the halogen - attached carbon. Methane can not be obtained by this method. The reaction fails in case of tertiary halides. See also Wurtz -- Fittig reaction References Jump up ^ March Advanced Organic Chemistry 5th edition p. 535 Jump up ^ Gary M. Lampman and James C. Aumiller `` Bicyclo ( 1.1. 0 ) butane '' Organic Syntheses, 1971, volume 51, pp 55 - 9. doi : 10.15227 / orgsyn. 051.0055 Aditya Krishna `` Dihalides Quartz '' Adolphe Wurtz ( 1855 ). `` Sur une nouvelle classe de radicaux organiques ''. Annales de chimie et de physique. 44 : 275 -- 312. Adolphe Wurtz ( 1855 ). `` Ueber eine neue Klasse organischer Radicale ''. Annalen der Chemie und Pharmacie. 96 ( 3 ) : 364 -- 375. doi : 10.1002 / jlac. 18550960310. Organic-chemistry.org Organic Chemistry, by Morrison and Boyd Organic Chemistry, by Graham Solomons and Craig Fryhle, Wiley Publications Retrieved from `` https://en.wikipedia.org/w/index.php?title=Wurtz_reaction&oldid=830434063 '' Categories : Coupling reactions Condensation reactions Carbon - carbon bond forming reactions Name reactions Hidden categories : Use dmy dates from May 2013 All articles with unsourced statements Articles with unsourced statements from April 2016 Talk Contents About Wikipedia Azərbaycanca Български Català Deutsch Español فارسی Français 한국어 Հայերեն Italiano Кыргызча Magyar Македонски Nederlands 日本 語 Polski Português Română Русский Suomi தமிழ் Українська Tiếng Việt 中文 16 more Edit links This page was last edited on 14 March 2018, at 20 : 10. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: why dry ether is used in woods reaction
Answer: to form a higher alkane; to form a higher alkane