The total syntheses of codonopsinine (1) and 4-epi-codonopsinine (2) were accomplished. The key substituted pyrrole intermediate was constructed via gold-catalyzed addition-cyclization cascade of an aminoacetaldehyde acetal derivative and a terminal alkyne. After diastereoselective reduction of the pyrrole intermediate to the corresponding 3-pyrroline derivative with zinc dust and sulfonic acid, the total synthesis of 4-epi-codonopsinine (2) was achieved via stereoselective construction of the diol by dihydroxylation. In addition, the total synthesis of codonopsinine (1) was completed through stereochemical inversion of the hydroxyl group via epoxide and subsequent ring cleavage under the acidic aqueous condition.

Download full-text PDF

Source
http://dx.doi.org/10.1038/ja.2016.13DOI Listing

Publication Analysis

Top Keywords

total syntheses
8
syntheses codonopsinine
8
codonopsinine 4-epi-codonopsinine
8
pyrrole intermediate
8
total synthesis
8
total
4
4-epi-codonopsinine gold-mediated
4
gold-mediated tandem-catalyzed
4
tandem-catalyzed pyrrole
4
pyrrole synthesis
4

Similar Publications

Large Language Models in Worldwide Medical Exams: Platform Development and Comprehensive Analysis.

J Med Internet Res

December 2024

Joint Laboratory of Artificial Intelligence for Critical Care Medicine, Department of Critical Care Medicine and Institutes for Systems Genetics, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, China.

Background: Large language models (LLMs) are increasingly integrated into medical education, with transformative potential for learning and assessment. However, their performance across diverse medical exams globally has remained underexplored.

Objective: This study aims to introduce MedExamLLM, a comprehensive platform designed to systematically evaluate the performance of LLMs on medical exams worldwide.

View Article and Find Full Text PDF

Prevalence and risk factors of sarcopenia in patients with stroke: a systematic review and meta-analysis.

Neurosurg Rev

December 2024

Evidence-Based Nursing-Center, School of Nursing, Lanzhou University, 730010, No.28, West Yan Road, Chengguan District, Lanzhou, Gansu Province, China.

Stroke is the second leading cause of death and the third-leading cause of disability in the world. The skeletal muscles play a key role in disability following stroke. Although many studies have reported the prevalence and risk factors of sarcopenia in patients with stroke, the results have not been synthesized.

View Article and Find Full Text PDF

Mycolactone is a complex macrolide toxin produced by , the causative agent of Buruli ulcer. The aim of this paper is to review the chemistry, biosynthetic, and synthetic pathways of mycolactone A/B to help develop an understanding of the mode of action of these polyketides as well as their therapeutic potential. The synthetic work has largely been driven by the desire to afford researchers enough (≥100 mg) of the pure toxins for systematic biological studies toward understanding their very high biological activities.

View Article and Find Full Text PDF

Objective: This systematic review aimed to identify the most prevalent conflict management styles and strategies employed by nurses in clinical settings and to examine the factors associated with their selection.

Methods: A comprehensive literature search was conducted following the PRISMA guidelines. Databases searched included PUBMED, CINAHL, Medline, and ProQuest, focusing on articles published between 2014 and 2024.

View Article and Find Full Text PDF

Background: Loneliness can occur at any age, but it is more prevalent among older adults due to the associated risk factors. Various interventions exist to improve this situation, but little is known about their long-term effects. Our aims were to determine if these interventions have long-lasting effects and for how long they can be sustained.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!