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Walter Dieckmann
Walter Dieckmann (8 October 1869 – 12 January 1925) was a German chemist. He is the namesake of the Dieckmann condensation, the intramolecular reaction of diesters with base to give β-keto esters. Dieckmann studied at the University of Munich and became assistant of Adolf von Baeyer Johann Friedrich Wilhelm Adolf von Baeyer (; 31 October 1835 – 20 August 1917) was a German chemist who synthesised indigo dye, indigo and developed a Von Baeyer nomenclature, nomenclature for cyclic compounds (that was subsequently extended a .... 1869 births 1925 deaths 20th-century German chemists Academic staff of the Ludwig Maximilian University of Munich BASF people 19th-century German chemists {{Germany-chemist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamburg
Hamburg (, ; ), officially the Free and Hanseatic City of Hamburg,. is the List of cities in Germany by population, second-largest city in Germany after Berlin and List of cities in the European Union by population within city limits, 7th-largest in the European Union with a population of over 1.9 million. The Hamburg Metropolitan Region has a population of over 5.1 million and is the List of EU metropolitan areas by GDP, eighth-largest metropolitan region by GDP in the European Union. At the southern tip of the Jutland Peninsula, Hamburg stands on the branching River Elbe at the head of a estuary to the North Sea, on the mouth of the Alster and Bille (Elbe), Bille. Hamburg is one of Germany's three city-states alongside Berlin and Bremen (state), Bremen, and is surrounded by Schleswig-Holstein to the north and Lower Saxony to the south. The Port of Hamburg is Germany's largest and Europe's List of busiest ports in Europe, third-largest, after Port of Rotterdam, Rotterda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germany
Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total population of over 84 million in an area of , making it the most populous member state of the European Union. It borders Denmark to the north, Poland and the Czech Republic to the east, Austria and Switzerland to the south, and France, Luxembourg, Belgium, and the Netherlands to the west. The Capital of Germany, nation's capital and List of cities in Germany by population, most populous city is Berlin and its main financial centre is Frankfurt; the largest urban area is the Ruhr. Settlement in the territory of modern Germany began in the Lower Paleolithic, with various tribes inhabiting it from the Neolithic onward, chiefly the Celts. Various Germanic peoples, Germanic tribes have inhabited the northern parts of modern Germany since classical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Munich
Munich is the capital and most populous city of Bavaria, Germany. As of 30 November 2024, its population was 1,604,384, making it the third-largest city in Germany after Berlin and Hamburg. Munich is the largest city in Germany that is not a state of its own. It ranks as the 11th-largest city in the European Union. The metropolitan area has around 3 million inhabitants, and the broader Munich Metropolitan Region is home to about 6.2 million people. It is the List of EU metropolitan regions by GDP#2021 ranking of top four German metropolitan regions, third largest metropolitan region by GDP in the European Union. Munich is located on the river Isar north of the Alps. It is the seat of the Upper Bavaria, Upper Bavarian administrative region. With 4,500 people per km2, Munich is Germany's most densely populated municipality. It is also the second-largest city in the Bavarian language, Bavarian dialect area after Vienna. The first record of Munich dates to 1158. The city ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BASF
BASF SE (), an initialism of its original name , is a European Multinational corporation, multinational company and the List of largest chemical producers, largest chemical producer in the world. Its headquarters are located in Ludwigshafen, Germany. BASF comprises subsidiary, subsidiaries and joint ventures in more than 80 countries, operating six integrated production sites and 390 other production sites across Europe, Asia, Australia, the Americas and Africa. BASF has customers in over 190 countries and supplies products to a wide variety of industries. Despite its size and global presence, BASF has received relatively little public attention since it abandoned the manufacture and sale of BASF-branded consumer electronics products in the 1990s. The company began as a dye manufacturer in 1865. Fritz Haber worked with Carl Bosch, one of its employees, to invent the Haber-Bosch, Haber-Bosch process by 1912, after which the company grew rapidly. In 1925, the company merged with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Munich
The Ludwig Maximilian University of Munich (simply University of Munich, LMU or LMU Munich; ) is a public university, public research university in Munich, Bavaria, Germany. Originally established as the University of Ingolstadt in 1472 by Duke Ludwig IX of Bavaria-Landshut, it is Germany's List of universities in Germany, sixth-oldest university in continuous operation. In 1800, the university was moved from Ingolstadt to Landshut by King Maximilian I Joseph of Bavaria when the city was threatened by the French, before being transferred to its present-day location in Munich in 1826 by King Ludwig I of Bavaria. In 1802, the university was officially named Ludwig-Maximilians-Universität by King Maximilian I of Bavaria in honor of himself and Ludwig IX. LMU is currently the second-largest university in Germany in terms of student population; in the 2023/24 winter semester, the university had a total of 52,972 matriculated students. Of these, 10,138 were freshmen, while internati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adolf Von Baeyer
Johann Friedrich Wilhelm Adolf von Baeyer (; 31 October 1835 – 20 August 1917) was a German chemist who synthesised indigo dye, indigo and developed a Von Baeyer nomenclature, nomenclature for cyclic compounds (that was subsequently extended and adopted as part of the IUPAC nomenclature of organic chemistry, IUPAC organic nomenclature). He was nobility, ennobled in the Kingdom of Bavaria in 1885 and was the 1905 recipient of the Nobel Prize in Chemistry.''Adolf von Baeyer: Winner of the Nobel Prize for Chemistry 1905 '' Armin de Meijere Angewandte Chemie International Edition Volume 44, Issue 48, Pages 7836 – 7840 2005''Abstract/ref> Family and education Baeyer was born in Berlin as the son of the noted geodesist and captain of the Royal Prussian Army Johann Jacob Baeyer and his wife Eugenie Baeyer née Hitzig (1807–1843). Both his parents were Lutherans at the time of his birth and he was raised in the Lutheran religion. His mother was the daughter of Julius Eduard Hitzig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dieckmann Condensation
The Dieckmann condensation is the Intramolecular reaction, intramolecular chemical reaction of ester, diesters with base to give β-keto esters. It is named after the German chemist Walter Dieckmann (1869–1925). The equivalent intermolecular reaction is the Claisen condensation. Dieckmann condensations are highly effective routes to 5-, 6-, and 7-member rings, but poor for larger rings. : Reaction mechanism Deprotonation of an ester at the α-position generates an enolate ion which then undergoes a Baldwin's rules, 5-exo-trig nucleophilic attack to give a cyclic enol. Protonation with a Brønsted–Lowry acid (H3O+ for example) re-forms the β-keto ester. : Due to the steric stability of five- and six-membered rings, these structures will preferentially be formed. 1,6 diesters will form five-membered cyclic β-keto esters, while 1,7 diesters will form six-membered β-keto esters. Further reading *Dieckmann, W. ''Chemische Berichte, Ber.'' 1894, ''27'', 102 & 965 *Dieckmann, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intramolecular Reaction
In chemistry, intramolecular describes a Chemical process, process or characteristic limited within the Chemical structure, structure of a single molecule, a property or phenomenon limited to the extent of a single molecule. Relative rates In intramolecular organic reactions, two reaction sites are contained within a single molecule. This configuration elevates the effective concentration of the reacting partners resulting in high reaction rates. Many intramolecular reactions are observed where the intermolecular version does not take place. Intramolecular reactions, especially ones leading to the formation of 5- and 6-membered rings, are rapid compared to an analogous intermolecular process. This is largely a consequence of the reduced entropic cost for reaching the transition state of ring formation and the absence of significant strain associated with formation of rings of these sizes. For the formation of different ring sizes via cyclization of substrates of varying tether ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Reaction
A chemical reaction is a process that leads to the chemistry, chemical transformation of one set of chemical substances to another. When chemical reactions occur, the atoms are rearranged and the reaction is accompanied by an Gibbs free energy, energy change as new products are generated. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the Atomic nucleus, nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive Chemical element, elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reagent, reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more Product (c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ester
In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distinctive functional group. Analogues derived from oxygen replaced by other chalcogens belong to the ester category as well. According to some authors, organyl derivatives of acidic hydrogen of other acids are esters as well (e.g. amides), but not according to the IUPAC. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Lactones are cyclic carboxylic esters; naturally occurring lactones are mainly 5- and 6-membered ring lactones. Lactones contribute to the aroma of fruits, butter, cheese, vegetables like celery and other foods. Esters can be formed from oxoacids (e.g. esters of acetic acid, carbonic acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base (chemistry)
In chemistry, there are three definitions in common use of the word "base": '' Arrhenius bases'', '' Brønsted bases'', and '' Lewis bases''. All definitions agree that bases are substances that react with acid An acid is a molecule or ion capable of either donating a proton (i.e. Hydron, hydrogen cation, H+), known as a Brønsted–Lowry acid–base theory, Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis ...s, as originally proposed by Guillaume-François Rouelle, G.-F. Rouelle in the mid-18th century. In 1884, Svante Arrhenius proposed that a base is a substance which dissociates in aqueous solution to form hydroxide ions OH−. These ions can react with Hydron (chemistry), hydrogen ions (H+ according to Arrhenius) from the dissociation of acids to form water in an acid–base reaction. A base was therefore a metal hydroxide such as NaOH or Calcium hydroxide, Ca(OH)2. Such aqueous hydroxide solutions were also described by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1869 Births
Events January * January 3 – Abdur Rahman Khan is defeated at Tinah Khan, and exiled from Afghanistan. * January 5 – Scotland's second oldest professional football team, Kilmarnock F.C., is founded. * January 20 – Elizabeth Cady Stanton is the first woman to testify before the United States Congress. * January 21 – The P.E.O. Sisterhood, a philanthropic educational organization for women, is founded at Iowa Wesleyan College in Mount Pleasant, Iowa. * January 27 – The Republic of Ezo is proclaimed on the northern Japanese island of Ezo (which will be renamed Hokkaidō on September 20) by remaining adherents to the Tokugawa shogunate. February * February 5 – Prospectors in Moliagul, Victoria, Australia, discover the largest alluvial gold nugget ever found, known as the " Welcome Stranger". * February 20 – Ranavalona II, the Merina Queen of Madagascar, is baptized. * February 25 – The Iron and Steel Institute is form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
