Organic Synthesis

6 Key excerpts on "Organic Synthesis"

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  Organic Synthesis and Organic Reagents

  • Ramesh Chandra, Snigdha Singh, Aarushi Singh(Authors)
  • 2020(Publication Date)
  • Arcler Press

    (Publisher)

  Organic Synthesis is a subdiscipline of synthesis. It is the art and science of constructing natural or designed substances. The main element of these substances is carbon. Total Synthesis is the flagship of Organic Synthesis, the endeavor of synthesizing Introduction to Organic Synthesis 3 the molecules of living nature in the laboratory setting (Figure 1.1). Figure 1.1. German scientists Friedrich Wöhler pioneered Organic Synthesis. Source: Image by Wikimedia Commons. The ability of an individual to replicate the molecules of living creatures, and make other molecules similar to them, is a remarkable development in history of humans. Its birth goes back to the year 1828, when Friedrich Wöhler, a German chemist and a Foreign Member of the Royal Society (ForMemRS), synthesized urea. It is an example of a naturally occurring substance from the living world. Such kind of molecules is commonly called natural products. This term generally refers to the secondary metabolites. The creative nature of total synthesis earned this discipline the privilege of being known as a fine art as well as a precise science. All the technologies that are derived from it, and Organic Synthesis in general, have given rise to an impressive host of advantages to society. These advantages include useful products that are ranging from dyes, pharmaceuticals, cosmetics, and agricultural chemicals to diagnostics and high-technology materials that is used in mobile phones, computers, and spaceships. Organic Synthesis is considered, to a large extent, to be accountable for some of the most exciting as well as significant discoveries of the 20 th century Organic Synthesis and Organic Reagents 4 in the field of biology , chemistry, and medicine. Also, it continues to fuel the discovery of the drug and development process with myriad processes and compounds for new biomedical applications and breakthroughs.

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  Chemistry: The Impure Science

  • Bernadette Bensaude-vincent, Jonathan Simon(Authors)
  • 2008(Publication Date)
  • ICP

    (Publisher)

  The resulting edifice of organic chemical theory enables us, with obvious con-sequences for Organic Synthesis, to assert that the outcome of very few organic reactions is unexpected, and fewer inexplicable. 16 Beyond the considerations of molecular structure of organic compounds, synthesis has played a vital role in much more fundamental theoretical developments. Indeed, the determination of energy values associated with molecular and atomic orbitals that can be estimated using Schrödinger’s equation can only be verified by means of carefully controlled syntheses which are capable of generating measurable indices. Nevertheless, all these organic syntheses are founded on a representation of molecular structure, and are not at all conceived of as being simply analysis in reverse. These syntheses mobilize a projected world constructed by human thought that remains fictional until the synthesis has been successfully completed. 108 Chemistry — The Impure Science Of course, with the rise of digital molecular modelling, these fictions often assume a virtual form as well. After conception, the organic chemist oper-ates with the available tools to construct the molecule in question, adding and removing groups as if operating with an elaborate “Meccano” kit. The ability to use this kit composed of standard reagents along with useful reac-tions or specific physical conditions conducive to one orientation or another cannot be reduced to an overarching chemical theory or even a well-defined set of general laws. A Creative Process Theory plays more than one role in the domain of Organic Synthesis. In addition to helping the chemist to plan the series of reactions that will lead to the desired compound, it also serves to indicate potential obstacles or pitfalls. How can we synthesize compounds that are theoretically possible? Indeed, as we have just been arguing, the creation of an “artificial” molecule is not a simple process of deduction from a theory or even a set of theories.

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  Chemistry: The Impure Science (2nd Edition)

  The Impure Science

  • Jonathan Simon, Bernadette Bensaude-vincent(Authors)
  • 2012(Publication Date)
  • ICP

    (Publisher)

  16 Chemistry Creates its Object 109 The creation of artefacts — in the literal sense of objects made or manufactured by human beings — is not, therefore, simply a technologi-cal by-product of chemical research. Before becoming industrial products, these artefacts served as a means for establishing chemical knowledge. Even today, synthesis is not exclusively a way of satisfying technological demands, but remains a privileged tool for understanding the nature of chemical compounds. Indeed, the majority of our knowledge concerning the molecular structure of organic compounds derives from nineteenth-century syntheses, starting with molecules like alizarine and indigo and including Emil Fischer’s synthesis of polypeptides and tannins. The tech-niques developed to create these products were not, however, limited to these initial applications. The various substitution reactions provided the means for generating a potentially infinite number of compounds, of which, inevitably, only a minority had any naturally occurring analogues. Organic Synthesis necessarily implied a dialogue between theory and practice, reflecting its potential not only for exploring the configuration of particular molecules but also for verifying quite general theories. Woodward considered that this exchange between theory and practice constituted the basis of a “second revolution” in organic chemistry. This followed a “first revolution” introduced by the structural theories proposed by Laurent and Kekulé. It is our view that organic chemistry has just passed through its second great revolution. The structure theory recognized that the maintenance of nearest-neighbor relationships among elements was responsible for the variety and individuality of the material components of the physical world.

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  Organic Synthesis

  The Science Behind the Art

  • W A Smit, A F Bochkov, R Caple(Authors)
  • 2007(Publication Date)
  • Royal Society of Chemistry

    (Publisher)

  This route of self-development was a natural and unavoidable occupation for the immature science of organic chemistry. Now, when millions of organic compounds have already been described and their basic classes studied rather thoroughly, such a ‘synthesis for the sake of synthesis’ may seem extravagant. It is a most difficult dilemma to ascertain whether it is actually worthwhile to appropriate resources from a goal-orientated investigation to the synthesis of Goals of an Organic Synthesis 35 yet another million new compounds*, not knowing in advance if they will be useful. As is the case with every fundamental science, organic chemistry probes the unknown. It is impossible to predict whether or not a significant discovery in some particular area may or may not happen. Even less can be said about the practical applications of potential discoveries. With certainty, however, one can predict that if organic chemistry is arrested in its evolution, both the discoveries in unexplored areas and their further applications will never occur. Chemists who synthesized cholesterol benzoate about 100 years ago, a routine synthesis of a derivative of a known compound, had no way of knowing that they had opened a route to the creation of innumerable and various devices in which liquid crystals are used. This new state of a material was unexpectedly discovered in the course of studies which were narrowly focused at the preparation of various derivatives from the readily available natural compound cholesterol. Similarly, the epoch of modern chemotherapy originated with the discovery of ‘sulfa drugs’, which happened as an absolutely unexpected consequence in a broad investigation aimed at the synthesis of hundreds of most diversified derivatives of aromatic compounds, potentially useful as components of azo dyes. The chemistry of fluoro organic compounds may serve as a typical example of the creation of a novel exploration solely for investigation purposes.

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  Computer Chemistry

  • Mario Marsili(Author)
  • 2017(Publication Date)
  • CRC Press

    (Publisher)

  Chapter 7 Computer Simulation of Organic Reactions

  I. Introduction

  Since the birth of organic chemistry as a science dealing with the synthesis and characterization of molecules containing a carbon skeleton, two fundamental questions have usually plagued every experimental organic chemist:

  • How can I synthesize a given target molecule?
  • Given a certain substrate molecule, how will it react under given conditions?

  The first question calls for a retrosynthetic approach to a synthesis problem, i.e., we have a synthesis design problem; the second question requires a forward search approach, i.e., deals with a reaction prediction problem.

  It is evident the these two paramount questions will receive different interpretations depending on whether they are formulated in an academic or in an industrial environment. In a university laboratory, priority is given to a successful synthesis of an interesting, structurally novel, and challenging target molecule, disregarding yield at the beginning; much interest is also devoted to the development of new reaction schemes. The creation act is the chemist's goal; the acknowledgment of the intellectual achievement is his reward.

  In industry, which has a profit-oriented organization, the molecule of interest must be obtained at a high yield at the lowest possible cost. Different considerations dominate here, and the "beauty" of a synthetic route experienced in an academic world might easily be lost by a brute high-temperature catalytic conversion in a production plant. Furthermore, the number of compounds synthesized in industry is extremely high: to obtain one pharmacologically active compound which passes all mandatory tests for release on the market, many hundreds or thousands of different species must be synthesized. Sometimes this procedure is not different from a wild, random search for some new lead compound, which might introduce a new class of drugs and then initiate a more systematic investigation.

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  Biorenewable Resources

  Engineering New Products from Agriculture

  • Robert C. Brown, Tristan R. Brown(Authors)
  • 2013(Publication Date)
  • Wiley-Blackwell

    (Publisher)

  CHAPTER 3 Organic Chemistry 3.1 Introduction

  Organic chemistry provides the foundation for understanding the transformation of plant materials into biofuels and biobased products. This chapter provides an overview to the subject for readers who are not familiar with the topic or require a brief review. More detailed descriptions can be found in the references at the end of this chapter.

  The original distinction between inorganic and organic compounds was their source in nature. Inorganic compounds were derived from mineral sources, whereas organic compounds were obtained from plants or animals. Advances in chemical synthesis since the eighteenth century have made obsolete these definitions: the vast majority of organic chemicals commercially produced today are made from petroleum. The common feature of organic compounds is a skeleton of carbon atoms that include lesser amounts of other atoms, especially hydrogen, oxygen, and nitrogen, but also sulfur, phosphorus, and halides.

  The high chemical valence of carbon allows for complex structures and large numbers of organic compounds. These include compounds consisting of chains of carbon atoms, referred to as acyclic or aliphatic compounds, and compounds containing rings of carbon atoms, known as carbocyclic or simply cyclic compounds. Some of these rings contain at least one atom that is not carbon (known as heteroatoms). These compounds are called heterocyclic compounds. Carbocyclic compounds are further classified as either aromatic compounds, in which electrons are shared among atoms to produce a particularly stable ring, or alicyclic compounds, which includes all non-aromatic cyclic compounds.

  3.2 Classification of Reactions

  A variety of reactions can occur among organic compounds. Addition reactions occur when two reactants combine to give a single product. Elimination reactions involve the splitting of a single compound into two compounds. Most elimination reactions form a product with a double bond containing the majority of the atoms found in the reactant. Substitution reactions involve replacement of one atom or group of atoms by a second atom or group of atoms. Hydrolysis is a particularly important instance of substitution reactions involving the action of water in splitting a large reactant molecule into two smaller product molecules. One product molecule is bonded to the hydrogen atom from the water, while the other product molecule is bonded to the hydroxyl group derived from the water. Condensation reactions involve two reactants combining to form one larger product with the simultaneous formation of a second, smaller product. Dehydration is a particularly important instance of condensation reactions in which water is the second, smaller product. Note that dehydration is the opposite of hydrolysis. Rearrangement

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