Name reactions

The above-described rearrangement reactions are not the only ones presented within this book. In addition to electrocyclic rearrangements, some rearrangements dependent upon ionic mechanisms were presented. These include the pinacol rearrangement 

While mechanistically distinct, the aldol condensation and the Friedel-Crafts acylation result in the incorporation of additional carbon atoms to the starting structure. This type of extension is extremely important when planning the synthesis of more complex organic molecules. To this end, the greater the number of available reactions, the greater the versatility in synthetic planning. 

Several outstanding books on name reactions in organic chemistry are available. These typically briefly cover the classic indole name reactions with examples, references, and, in some cases, experimental procedures. 

Li and J.M. Cook (2005) Indoles, in Name Reactions in Heterocyclic Chemistry (ed. J.-J. Li), Wiley-Interscience, Hoboken, New Jersey, Chapter 3, pp. 99-158. 

Ellerd, and F.G. Favaloro, Jr. (2005) Name Reactions and Reagents in Organic Synthesis, 2nd Edn., WUey-Interscience, Hoboken, New Jersey. 

Kruiswijk (2005) The Comprehensive e-Book of Name Organic Reactions and Their Mechanisms, 2nd edn. hnk.springer.com/ content/pdf/10.2478/EF02479284.pdf J.J. Li (2002) Name Reactions, Springer, Berlin. 

Hassner and C. Stumer (2002) Organic Syntheses Based on Name Reactions, 2nd edn, Pergamon, Amsterdam. 

Some organic transformations are frequently used in chemical synthesis in both laboratory and industry. These are termed as name reactions [23]. Here, we will discuss a few important name reactions and provide detailed reaction modelling steps for the Diels-Alder reaction which is a typical carbon-carbon bond-forming cycloaddition transformation that proceeds with high stereocontrol. 

Aldol Reaction (Condensation) [24] Traditionally, it is the acid- or base-catalyzed condensation of one carbonyl compound with the enolate/enol of another, which may or may not be the same, to generate a P-hydroxy carbonyl compound— an aldol. The method is composed of self-condensation, polycondensation, generation of regioisomeric enols/enolates, and dehydration of the aldol followed by Michael addition, q.v. The development of methods for the preparation and use of preformed enolates or enol derivatives that dictate specific caibon-caibon bond formation have revolutionized the coupling of carbonyl compounds (Fig. 6.6)  

Cope rearrangement [25] The highly stereoselective [3,3] sigmatropic rearrangement of 1,5 dienes is called as Cope rearrangement. When the R group is an alcohol, it is called as oxy-Cope rearrangement (Fig. 6.7). 

Claisen Condensation (Acetoacetic Ester Condensation) [26] Base-catalyzed condensation of an ester containing an a-hydrogen atom with a molecule of the same ester or a different one to give p-keto esters (Fig. 6.8)  

Chugaev elimination [27] This reaction involves the formation of alkenes through pyrolysis of the corresponding xanthates via cis elimination  

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Syntheses are no longer viewed in terms of known name reactions and single steps, but as the global transformation of a skeleton and its pattern of polarities and potential charges obtained through the lieterolysis of a bond that can be stabilised by entire classes of substituents. 

The last-named reaction provides an excellent method for the preparation of a-substituted glutaric acids the intermediate alkyl (aryl) -2-cyanoethyl-malonate is both hydrolysed and decarboxylated re ily by boiling with an excess of 48 per cent, hydrobromic acid solution. 

Surrey, Name Reactions in Organic Chemistry, 1954 (Academic Press). 

Aldol additions and ester condensations have always been and still are the most popular reactions for the formation of carbon-carbon bonds (A.T. Nielsen, 1968). The earbonyl group acts as an a -synthon, the enoi or enolate as a d -synthon. Both reactions will be treated together here, and arguments, which are given for aldol additions, are also valid for ester condensations. Many famous name reactions belong to this category ). The products of aldol additions may be either /J-hydroxy carbonyl compounds or, after dehydration, or, -unsaturated carbonyl compounds. 

A. R. Surrey, Name Reactions in Organic Chemisty 2nd ed.. Academic Press, Inc., New York, 1961. 

Ba.se Catalyzed. Depending on the nature of the hydrocarbon groups attached to the carbonyl, ketones can either undergo self-condensation, or condense with other activated reagents, in the presence of base. Name reactions which describe these conditions include the aldol reaction, the Darzens-Claisen condensation, the Claisen-Schmidt condensation, and the Michael reaction. 

The chemistry of ethyl alcohol is largely that of the hydroxyl group, namely, reactions of dehydration, dehydrogenation, oxidation, and esterification. The hydrogen atom of the hydroxyl group can be replaced by an active metal, such as sodium, potassium, and calcium, to form a metal ethoxide (ethylate) with the evolution of hydrogen gas (see Alkoxides, metal). 

This index contains over 40,000 individual entries to the 6200 text pages of Volumes 1-7. The index mainly covers general classes of heterocyclic compound and specific heterocyclic compounds, but also included are natural products, other organic and organometallic compounds where their synthesis or use involves heterocyclic compounds, types of reaction, named reactions, spectroscopic techniques and topics involving heterocyclic compounds. 

The Subject Index of over 20 000 entries has been compiled from keywords, names and formulae in the text and tables. It covers general classes of compound, specific compounds, general types of reaction, specific and named reactions, spectral and other properties, and other topics in heterocyclic chemistry. More details are again given at the beginning of the index in Volume 8. 

In recent years there has been a proliferation of new reactions and reagents that have been so useful in organic synthesis that often people refer to them by name. Many of these are stereoselective or regioselecth/e methods. While the expert may know exactly what the Makosza vicarious nucleophilic substitution, or the Meyers asymmetric synthesis refers to, many students as well as researchers would appreciate guidance regarding such "Name Reactions". 

It is in this context that we perceived the necessity to incorporate the oider name reactions with some newer name reactions or "unnamed reactions , that are often associated with a name but for which details, references and experimental details are not at everyone s fingertips. This was our inspiration for the current monograph "Organic Syntheses based on Name Reactions and Unnamed Reactions . 

The choice of which reactions to include is not an easy one. First there are the well known "Name Reactions", that have appeared in various monographs or in the old Merck index. Some of these are so obvious mechanistically to the modern organic chemistry practitioner that we have in fact omitted them for instance esterification of alcohols with acid chlorides - the Schotten-Baumann procedure. Others are so important and so well entrenched by name, like the Baeyer-Villiger ketone oxidation, that it is impossible to ignore them. In general we have kept older name reactions that are not obvious at first glance. 

Among the newer reactions we have chosen those that are not only synthetically useful but at first glance not immediately obvious transformations. Another criterion was the stereochemical implications of the process. Yet, we admit our own bias in choosing from the plethora of novel transformations that have appeared in the literature over the past 30 years or so. Space limitation was by necessity a criterion. Nevertheless we have included approximately 450 name reactions and 2100 references. We sincerely apologize if we have inadvertedly omitted important reactions. 

Mundy, B.P. and Ellard, M.G., Name Reactions and Reagents in Organic Synthe.sis. Wiley-Interscience, New York, 1988. 

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