14782-52-6Relevant academic research and scientific papers
Total Synthesis of 1-Hydroxytaxinine
Imamura, Yusuke,Yoshioka, Shun,Nagatomo, Masanori,Inoue, Masayuki
supporting information, p. 12159 - 12163 (2019/08/02)
1-Hydroxytaxinine (1) is a cytotoxic taxane diterpenoid. Its central eight-membered B-ring possesses four oxygen-functionalized centers (C1, C2, C9, and C10) and two quaternary carbon centers (C8 and C15), and is fused with six-membered A- and C-rings. The densely functionalized and intricately fused structure of 1 makes it a highly challenging synthetic target. Reported here is an efficient radical-based strategy for assembling 1 from A- and C-ring fragments. The A-ring bearing an α-alkoxyacyl telluride moiety underwent intermolecular coupling with the C-ring fragment by a Et3B/O2-promoted decarbonylative radical formation. After construction of the C8-quaternary stereocenter, a pinacol coupling reaction using a low-valent titanium reagent formed the B-ring with stereoselective installation of the C1,C2-diol. Subsequent manipulations at the A- and C-rings furnished 1 in 26 total steps.
NRF 2 ACTIVATOR
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Page/Page column 34; 35, (2018/08/20)
Provided are compounds of Formula I, or pharmaceutically acceptable salts thereof, which are activators of nuclear factor erythroid 2 (NF-E2) -related factor 2 (Nrf2) and are useful to treat diseases caused by oxidative stress, such as neurodegenerative diseases or inflammation. Also provided are methods for their use and production.
Enantioselective total syntheses of citrinadins A and B. Stereochemical revision of their assigned structures
Bian, Zhiguo,Marvin, Christopher C.,Pettersson, Martin,Martin, Stephen F.
, p. 14184 - 14192 (2015/02/18)
The concise, enantioselective total syntheses of (-)-citrinadin A and (+)-citrinadin B in a total of only 20 and 21 steps, respectively, from commercially available starting materials are described. Our strategy, which minimizes refunctionalization and protection/deprotection operations, features the highly diastereoselective, vinylogous Mannich addition of a dienolate to a chiral pyridinium salt to set the first chiral center. The absolute stereochemistry of this key center was then relayed by a sequence of substrate-controlled reactions, including a highly stereoselective epoxidation/ring opening sequence and an oxidative rearrangement of an indole to furnish a spirooxindole to establish the remaining stereocenters in the pentacyclic core of the citrinadins. An early stage intermediate in the synthesis of (-)-citrinadin A was deoxygenated to generate a dehydroxy compound that was elaborated into (+)-citrinadin B by a sequence of reaction identical to those used to prepare (-)-citrinadin A. These concise syntheses of (-)-citrinadin A and (+)-citrinadin B led to a revision of their stereochemical structures.
Enantioselective total synthesis of (-)-citrinadin A and revision of its stereochemical structure
Bian, Zhiguo,Marvin, Christopher C.,Martin, Stephen F.
supporting information, p. 10886 - 10889 (2013/08/23)
The first enantioselective total synthesis of (-)-citrinadin A has been accomplished in 20 steps from commercially available materials via an approach that minimizes refunctionalization and protection/deprotection operations. The cornerstone of this synthesis features an asymmetric vinylogous Mannich addition of a dienolate to a chiral pyridinium salt to set the initial chiral center. A sequence of substrate-controlled reactions, including a highly stereoselective epoxidation/ring-opening sequence and an oxidative rearrangement of an indole to furnish a spirooxindole, are then used to establish the remaining stereocenters in the pentacyclic core of (-)-citrinadin A. The successful synthesis of citrinadin A led to a revision of the stereochemical structure of the core substructure of the citrinadins.
Synthetic studies toward the citrinadin A and B core architecture
Mundal, Devon A.,Sarpong, Richmond
supporting information, p. 4952 - 4955 (2013/10/22)
The core architecture of the citrinadin alkaloids has been prepared in racemic form by utilizing a strategy that exploits the alkylation of 2-methoxypyridines. An initially planned indolizidine to quinolizidine transformation to build the D/E rings was unsuccessful. Success was ultimately gained by a direct alkylation to establish the citrinadin core architecture.
Chemoselective and chemospecific protection and deprotection of a carbonyl group using polystyrene divinylbenzene sulfonic acid
Verma, Sanjeev K.,Sathe, Manisha,Kaushik
experimental part, p. 1701 - 1707 (2010/07/15)
Chemospecific protection of one carbonyl group of two identical carbonyls of 2,2-dialkyl-1,3-cyclohexanedione and chemoselective protection of aliphatic or aromatic carbonyls in the presence of conjugated carbonyl compounds using cross-linked polystyrene divinyl benzene sulfonic acid (SPS) as a heterogeneous catalyst has been demonstrated. Copyright
A concise enantioselective synthesis of a fully oxygen substituted ring A taxol precursor
Roy, Olivier,Pattenden, Gerald,Pryde, David C.,Wilson, Claire
, p. 5115 - 5121 (2007/10/03)
A concise synthesis of the oxygen substituted ring A compound 2 found in Taxol 1a and Taxotere 1b starting from 2,2-dimethylcyclohexane-1,3-dione and proceeding via the key intermediates 8 and 11, is described. The absolute configuration of 2 was established from an X-ray crystal structure determination of a 4-bromophenylbenzoate derivative, viz. 15.
Design and synthesis of tubulin ligands based on epothilones: A preliminary study
Vielle, Sophie,Raimbaud, Eric,Bertrand, Philippe,Quintard, Delphine,Renard, Pierre,Pfeiffer, Bruno,Gesson, Jean-Pierre
, p. 9213 - 9216 (2007/10/03)
Starting from the X-ray structure of epothilone B, an original, non macrocyclic, structure has been designed to mimic the key structural features of this potent anticancer agent; the preparation of a key intermediate incorporating four stereogenic centers is described from cyclohexane-1,3-dione.
A Practical Total Synthesis of Taxamairin B
Ning, Chen,Wang, Xue-Chao,Pan, Xin-Fu
, p. 2115 - 2122 (2007/10/03)
Taxamairin B, a novel rearranged 9(10 -> 20)-abeo-8,11,13-triene diterpenoid, has been convergently synthesized by a facile route, which employed the acid catalyzed rearrangement and oxidation of vinyl carbinol as the key steps.
Synthesis of a diterpene taxoid skeleton, bicyclo[9.3.1]pentadecatriene
Shibuya, Satoshi,Isobe, Minoru
, p. 6677 - 6698 (2007/10/03)
The synthesis of bicyclo[9.3.1]pentadecatriene skeleton was investigated by employing cyclization reactions using two key precursors bearing acetylene cobalt complex. Cyclization for the synthesis of strained twelve-membered ring was achieved via Nicholas type reaction in reasonable yield. Reductive decomplexation of the dicobalt hexacarbonyl moiety of the cyclization product was achieved with n-Bu3SnH in the presence of a catalytic amount of NBS in 1,4-cyclohexadiene solvent.
