German chemists

During the nineteenth century it was widely believed—incorrectly as we 11 soon see— that cycloalkane rings are planar A leading advocate of this view was the German chemist Adolf von Baeyer He noted that compounds containing rings other than those... 

The 1967 Nobel Prize in chemistry was shared by Manfred Eigen a German chemist who developed novel methods for measur ing the rates of very fast re actions such as proton transfers... 

N substituted imines are sometimes called Schiff s bases after Hugo Schiff a German chemist who de scribed their formation in 1864... 

The reaction is named after Georg Wittig a German chemist who shared the 1979 Nobel Prize in chemistry for demonstrating its synthetic potential... 

Walter Dieckmann was a German chemist and a contemporary of Claisen... 

The key compound m the synthesis of aspirin salicylic acid is prepared from phe nol by a process discovered m the nineteenth century by the German chemist Hermann Kolbe In the Kolbe synthesis also known as the Kolbe—Schmitt reaction, sodium phen oxide IS heated with carbon dioxide under pressure and the reaction mixture is subse quently acidified to yield salicylic acid... 

The German chemist Otto Wallach (Nobel Prize m chemistry 1910) determined the structures of many terpenes and is credited with setting forth the isoprene rule ter penes are repeating assemblies of isoprene units normally joined head to tail... 

Stereochemistry deals with the three-dimensional ariangement of a molecule s atoms, and we have attempted to show stereochemistry with wedge-and-dash drawings and computergenerated models. It is possible, however, to convey stereochemical information in an abbreviated form using a method devised by the German chemist Emil Fischer. 

Ludwig Claisen was a German chemist who worked during the last two decades of the nineteenth century and the first two decades of the twentieth. His name is associated with three reactions. The Claisen-Schmidt reaction was presented in Section 18.10, the Claisen condensation is discussed in this section, and the Claisen rearrangement will be introduced in Section 24.13. 

The product of this reaction, as its sodium salt, is called a Meisenheimer complex after the German chemist Jacob Meisenheimer, who reported on their formation and reactions in 1902. A Meisenheimer complex corresponds to the product of the nucleophilic addition stage in the addition-elimination mechanism for nucleophilic aromatic substitution. 

German chemist Wilhelm Ostwald. He was awarded a Nobel Pri2e for his work on chemical equilibrium. fLibrary of Congress)... 

The German chemist J. BreclL proposed in 1935 that bicvcloalkenes such as 1-norbornene, which have a double bond to the bridgehead carbon, are too strained to exist. Make a molecular mode) of 1-norbornene, and explain Bredt s proposal. 

In 1896, the German chemist Paul Walden made a remarkable discovery. He found that the pure enantiomeric (+)- and (-)-malic acids could be intercon-veited through a series of simple substitution reactions. When Walden treated (-)-malic acid with PCl5, he isolated (4-)-chlorosuccinic acid. This, on treatment with wet Ag20, gave (+)-malic acid. Similarly, reaction of (+)-malic acid with... 

Chemists in the early 1900s believed that the only requirement for aromaticity was the presence of a cyclic conjugated system. It was therefore expected that cyclooctatetraene,. as a close analog of benzene, would also prove to be unusually stable. The facts, however, proved otherwise. When cyclooctatetraene was first prepared in 1911 by the German chemist Richard Willstatter, it was found not to be particularly stable but to resemble an open-chain polyene in its reactivity. 

Prior to World War I the principal sources of nitrogen compounds were some nitrate deposits in Chile. Fritz Haber, a German chemist, successfully developed the process we have just described, thus allowing chemists to use the almost unlimited supply of nitrogen in the atmosphere as a source of nitrogen compounds. 

The first striking fact here is that medal was awarded not to Mendeleev alone, but rather jointly to him and the German chemist Lothar Meyer. This already poses a problem for the predictivist thesis. Although Lothar Meyer s scheme was, as he himself pointed out, essentially identical to Mendeleev s, Meyer failed to draw attention to the existence of gaps in the periodicities displayed by the table and hence failed to predict new elements. Only Mendeleev explicitly derived the consequence that the scheme must be regarded as containing gaps and therefore only Mendeleev explicitly predicted the new elements.11... 

The closet precursor to Mendeleev s table in both chronological and philosophical toms was developed by Julius Lothar Meyer, a German chemist, in 1864. Although Meyer stressed physical rather than chemical properties, his table bears remarkable similarity to the one that Mendeleev would develop five years later. For a number of reasons, Meyer s prominence in tlte history books never matched Mendeleev s. There was an untimely delay in the publication of his most elaborate periodic table, and, perliaps more important, Meyer—unlike Mendeleev—hesitated to make predictions about unknown elements. 

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