Synthesis Of Quinine Research Articles

Possibility of quinine transformation in food products: LC\u2013MS and NMR techniques in analysis of quinine derivatives

Quinine is an alkaloid consisting of two major systems: quinoline and quinuclidine. It receives the attention of scientists because of its several medical properties: antimalarial, painkilling and fever-reducing properties. Moreover, it is widely used in food industry as a flavor component. Although the method of quinine synthesis is known, the most cost-effective is its isolation from its natural source, the bark of Cinchona tree. Liquid–solid extraction is the predominantly applied method for the isolation of active biological compounds from different plants. We found that the heating of the quinine in phosphoric buffer solution with low pH produced at least five compounds, whereas the heating of the quinine in alcohol/phosphoric buffer solution with decreased pH produced at least eight compounds. The formation of hydroxy and alkoxy adducts has not yet been reported. We observed that the amount of each formed component is dependent on the heating time, alcohol concentration in alcoholic/buffer mixture and pH. The presented results are particularly important in the context of the use of quinine as food ingredient, because quinine derivatives, quinine structural isomers and their derivatives can be formed in significant amounts and their influence on the human body has not been fully explored yet.

Synthesis of quinine and quinidine using sulfur ylide-mediated asymmetric epoxidation as a key step

The epoxidation of meroquinene aldehyde with a chiral sulfur ylide as the key step in the synthesis of quinine and quinidine is described. The epoxidation reactions proceed under reagent control with high selectivity and good yield. The effect of sulfide and ylide substituents on the stereochemical outcome of the reaction is discussed.

Quinina: 470 anos de história, controvérsias e desenvolvimento

After 470 years, a history of development, international seed smuggling and scientific development that caused deep changes in our society, has reached an end. In 1638, the countess of Chinchon contracted a disease while in the Amazon rain forest and was healed by a potion used by the native inhabitants. In 1856, William H. Perkin while attempting to obtain synthetic quinine, discovered the mauveina, a molecule that changed the world. The synthesis of quinine was also the subject of a bitter controversy among two excellent scientists of the 20th century. During centuries, quinine was the only hope against malaria disease and its exploration almost extinguished the Cinchona tree.

Molecule matters

Ever since its isolation in 1820, Quinine has played a crucial role in the development of organic chemistry, chemical industry and modern medicine. The total synthesis of quinine, widely regarded as anevent of epochal importancewas claimed by Woodward and Doering in 1945. This work, however, heavily relied on unsubstantiated literature reports and it appears that Woodward’s work fell short of a total synthesis of quinine. The first stereoselective total synthesis of quinine was accomplished only in 2001, by Stork, who incidentally is the originator of the concept of stereoselectivity in total synthesis. Naturally, this work has been attested as a landmark in organic synthesis by leaders in the field.

Salt-Free Enantioselective Iridium-Catalyzed Allylic Alkylations

Previous systems involving iridium-catalyzed allylic alkylations with β-carbonyl compounds require the use of the corresponding ­alkali-metal salt. The authors report iridium complexes of several phosphorus amidite ligands activated by the base TBD [1,5,7-triazabicyclo[4.4.0]dec-5-ene] which accommodate neutral β-carbonyl compounds. Further, the authors illustrate the utility of this method by providing a key intermediate in Stork’s quinine synthesis, the Ta­niguchi lactone, in high enantiomeric purity. Additionally, the catalytic system is applied to the intramolecular cyclization of 6 to yield cyclopropane 7 in high ee.

ChemInform Abstract: STEREOCONSERVATIVE TRANSFORMATION OF SECOLOGANIN INTO MEROQUINENE AND ITS DERIVATIVES

AbstractDas Tetraacetat von Secologanin (Ia) wird durch Iones‐ Oxidation, Methylierung mit Diazomethan und anschließende Zemplen‐Desacetylierung in das Methoxyderivat (Ib) umgewandelt, das nach Entfernung des Zuckerrestes mit β‐Glucosidase bei pH 6,5 mit Natriumcyanoborhydrid zur Vinylverbindung (II) reduktiv aminiert wird.

Stereoconservative transformation of secologanin into meroquinene and its derivatives

Short reaction sequences convert secologanin (1) into meroquinene and its derivatives (4) and (8), key intermediates in the synthesis of quinine (2) and related Cinchona alkaloids.

Reinvestigation of the Classical Synthesis of Cinchona Alkaloids. II. The synthesis of quinine and its naturally occurring diastereomers from quinotoxine

AbstractStereoselektive Synthesen der Cinchona Alkaloide Chinin (6) und seiner natürlich vorkommenden Diastereomeren 7, 8 und 9, ausgehend von Chinotoxin (2), werden beschrieben. Reduktion der Ketone 4 und 5 mit DIBAL ergibt ausschliesslich die C(8)–C(9) erythro‐Verbindungen Chinin und Chinidin, während Reduktion von 5 mit Natriumborhydrid ausnahmslos zu den epi‐Verbindungen 8 und 9 führt. Die letztgenannten Verbindungen werden selektiv auch auf einem anderen Weg über die erythro‐Epoxide 20 und 21 erhalten.

Stereospecific approach to the synthesis of quinine and related alkaloids

A stereospecific synthesis of syn-5-hydroxyalkyl-3-quinuclidines is described and their feasibility as intermediates in a new approach to the synthesis of cinchona alkaloids illustrated.

The Synthesis of Quinine

The Synthesis of Quinine

The Synthesis of Quinine

The Synthesis of Quinine