Tetrodotoxin (TTX) is a neurotoxic natural product that is an indispensable probe in neuroscience, a biosynthetic and ecological enigma, and a celebrated target of synthetic chemistry. Here, we present a stereoselective synthesis of TTX that proceeds in 22 steps from a glucose derivative. The central cyclohexane ring of TTX and its α-tertiary amine moiety were established by the intramolecular 1,3-dipolar cycloaddition of a nitrile oxide, followed by alkynyl addition to the resultant isoxazoline. A ruthenium-catalyzed hydroxylactonization set the stage for the formation of the dioxa-adamantane core. Installation of the guanidine, oxidation of a primary alcohol, and a late-stage epimerization gave a mixture of TTX and anhydro-TTX. This synthetic approach could give ready access to biologically active derivatives.
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http://dx.doi.org/10.1126/science.abn0571 | DOI Listing |
Front Neurol
December 2024
Neuromuscular Imaging Research Lab, The Kolling Institute, North Sydney Local Health District, St Leonards, NSW, Australia.
Individuals with joint hypermobility and the Ehlers-Danlos Syndromes (EDS) are disproportionately affected by neuraxial dysfunction and Central Nervous System (CNS) disorders: such as Spontaneous Intracranial Hypotension (SIH) due to spinal cerebrospinal fluid (CSF) leaks, Upper Cervical Instability (UCI; including craniocervical or atlantoaxial instability (CCI/AAI)), Occult Tethered Cord Syndrome (TCS), Chiari Malformation (CM) and Idiopathic Intracranial Hypertension (IIH). The neuraxis comprises the parts of the nervous system (brain, nerves, spinal cord) along the craniospinal axis of the body. Neuraxial tissue includes all tissue structures that comprise, support, sheath, and connect along the neuraxis and peripheral nerves.
View Article and Find Full Text PDFNature
December 2024
Department of Chemistry, Scripps Research, La Jolla, California, USA.
The synthesis of a complex molecule begins from an initial design stage in which possible routes are triaged by strategy and feasibility, based on analogy to similar reactions. However, as molecular complexity increases, predictability decreases; inevitably, even experienced chemists resort to trial-and-error to identify viable intermediates en route to the target molecule. We encountered such a problem in the synthesis of picrotoxane sesquiterpenes in which pattern recognition methods anticipated success, but small variations in structure led to failure.
View Article and Find Full Text PDFRNA Biol
December 2025
Baqiyatallah Research Center for Gastroenterology and Liver Diseases (BRCGL), Baqiyatallah University of Medical Sciences, Tehran, Iran.
Liver diseases are a significant global health issue, characterized by elevated levels of disorder and death. The substantial impact of ageing on liver diseases and their prognosis is evident. Multiple processes are involved in the ageing process, which ultimately leads to functional deterioration of this organ.
View Article and Find Full Text PDFJ Org Chem
December 2024
College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, People's Republic of China.
Due to its unique three-dimensional (3D) configuration and great application potential in medicinal chemistry and synthetic community, chemists have been pursuing concise and efficient methods to synthesize C3 spirocyclic indoline derivatives. In this work, a dearomatization-spirocyclization-nucleophilic addition tandem approach was developed to realize the synthesis of 2-phosphonylated C3 spirocyclic indolines with indolyl-ynones and phosphine oxides as reactants; mild conditions, broad substrate scope, and good yields are characteristics of this transformation.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
A concise synthesis of the complex diterpene azorellolide, inspired by speculations on biosynthetic cationic cascades, is presented. The approach, guided by computation, relies on the intramolecular interception of a cyclopropylcarbinyl cation by an appended carboxylate. The successful execution of this strategy was achieved through acid-catalyzed isomerization of a β-lactone in competition with a type I dyotropic rearrangement.
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