Figure 10.1 The gases released during volcanic eruptions contain large amounts of organohalides, including chloromethane, chloroform, dichlorodifluoromethane, and many others. (credit: modification of work “Tavurvur volcano” by Taro Taylor, Richard Bartz/Wikimedia Commons, CC BY 2.0) Chapter Contents 10.1 Names and Structures of Alkyl Halides…
Alkynes are less common than alkenes, both in the laboratory and in living organisms, so we haven’t covered them in great detail. The real importance of this chapter is that alkyne chemistry is a useful vehicle for looking at the…
Figure 9.8 Vitamin B12 has been synthesized from scratch in the laboratory, but the bacteria growing on sludge from municipal sewage plants do a much better job. (credit: “Aeration and sludge-wasting” by U.S. Department of Agriculture/Flickr, Public Domain) If you think some of…
As mentioned in the introduction, one of the purposes of this chapter is to use alkyne chemistry as a vehicle to begin looking at some of the general strategies used in organic synthesis—the construction of complex molecules in the laboratory.…
negative charge and unshared electron pair on carbon make an acetylide anion strongly nucleophilic. As a result, an acetylide anion can react with electrophiles, such as alkyl halides, in a process that replaces the halide and yields a new alkyne…
The most striking difference between alkenes and alkynes is that terminal alkynes are relatively acidic. When a terminal alkyne is treated with a strong base, such as sodium amide, Na+ −NH2, the terminal hydrogen is removed and the corresponding acetylide anion is formed.…
Alkynes, like alkenes, can be cleaved by reaction with powerful oxidizing agents such as ozone or KMnO4, although the reaction is of little value and it is mentioned only for completeness. A triple bond is generally less reactive than a…
Alkynes are reduced to alkanes by addition of H2 over a metal catalyst. The reaction occurs in two steps through an alkene intermediate, and measurements show that the first step in the reaction is more exothermic than the second. Complete reduction…
Like alkenes (Section 8.4 and Section 8.5), alkynes can be hydrated by either of two methods. Direct addition of water catalyzed by mercury(II) ion yields the Markovnikov product, and indirect addition of water by a hydroboration–oxidation sequence yields the non-Markovnikov product. Mercury(II)-Catalyzed…
You might recall from Section 1.9 that a carbon–carbon triple bond results from the interaction of two sp-hybridized carbon atoms. The two sp hybrid orbitals of carbon lie at an angle of 180° to each other along an axis perpendicular to the axes of the…