Efforts to establish an asymmetric entry to hexanorlanostanes has resulted in a concise synthesis of 7,11-dideoxy-Δ-lucidadone H from epichlorohydrin. By exploiting metallacycle-mediated annulative cross-coupling (to establish a functionalized hydrindane) and stereoselective formation of the steroidal C9-C10 bond to establish a stereodefined 9-alkyl estrane, 14 subsequent steps have been established to generate a hexanorlanostane system. Key transformations include formal inversion of the C13 quaternary center, oxidative dearomatization/group-selective Wagner-Meerwein rearrangement, and Lewis acid mediated semi-Pinacol rearrangement.
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http://dx.doi.org/10.1021/acs.joc.2c02042 | DOI Listing |
Mol Biol Cell
January 2025
Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA.
Asymmetric cell division (ACD) allows daughter cells of a polarized mother to acquire different developmental fates. In , the Wnt/β-catenin Asymmetry (WβA) pathway regulates many embryonic and larval ACDs; here, a Wnt gradient induces an asymmetric distribution of Wnt signaling components within the dividing mother cell. One terminal nuclear effector of the WβA pathway is the transcriptional activator SYS-1/β-catenin.
View Article and Find Full Text PDFNeuropediatrics
January 2025
Department of Neuroradiology, Great Ormond Street Hospital, London, United Kingdom.
We describe a set of monozygotic twins with Glutamate Ionotropic Receptor N-methyl-D-aspartate Type Subunit 2B-related neurodevelopmental disorder (GRIN2B-ND) who exhibited distinct clinical and imaging characteristics due to a de novo heterozygous pathogenic variant in the gene (c.2453T > C, p.Met818Thr).
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam 781039, India.
Herein, an organocatalytic asymmetric desymmetrizing [4+2] cycloaddition/base-mediated oxidative aromatization reaction sequence has been developed between spirophthalide 2,5-cyclohexadienones and β-methyl cinnamaldehydes. The reaction proceeds through chiral dienamine intermediate formation, and the densely functionalized spirocyclic isobenzofuranone-embedded chiral arenes were formed in high yields with excellent enantioselectivities. A 2-fold desymmetrization reaction was also performed, and the products were obtained in high enantioselectivities.
View Article and Find Full Text PDFOrg Biomol Chem
December 2024
Zhejiang Engineering Research Center of Fat-Soluble Vitamin, Shaoxing 312000, China.
The oxidative C2-C3 π bond activation strategy is the most efficient tool to synthesize oxygen-containing indoline, which frequently appears in natural products with various biological activities as structural units. Recently, the oxidation-induced cascade strategy through oxygenation activation of the indolic C2-C3 π bond of indoles has received much attention for its use in efficiently establishing complex indoline with oxygen-containing molecular architectures, and holds tremendous potential in the total synthesis of indole alkaloids. It can be carried out using potential activated indole radical cations or imine cation intermediates produced oxidative C2-C3 π bond activation of indole with various nucleophiles or ring-forming reagents by employing simple and non-decorated indoles as starting substrates.
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