相关实验视频
Updated: Jan 25, 2026

10:10
Reverse Total Shoulder Arthroplasty
Published on: July 5, 2011
43.9K
(+) 树脂的总合成
Zhiyao Zhou1, Alison X Gao1, Scott A Snyder1
1Department of Chemistry , University of Chicago , 5735 South Ellis Avenue , Chicago , Illinois 60637 , United States.
Journal of the American Chemical Society
|April 25, 2019
概括
研究人员首次实现了复杂的科普西亚醇类化合物arborisidine的全合成. 这涉及创建具有挑战性的四元碳中心的新方法,
科学领域:
- 有机化学
- 自然产品合成
- 医学化学
背景情况:
- 阿博里西丁是一种独特的Kopsia醇.
- 它的结构具有一个完全替代的环和两个四级碳.
- 合成这种复杂的结构在立体控制中带来了重大挑战.
研究的目的:
- 实现第一个全合成的arborisidine.
- 开发高效和刻板选择的方法来构建其复杂的核心.
- 为了探索新的合成策略,
主要方法:
- 这是一个由三胺制成的七步化学合成.
- 从d-甲基中进行9个步骤的不对称合成.
- 关键步骤包括一个化协议,用于aza-quaternary中心的形成和金属促进的enyne循环.
主要成果:
- 在racemic和不对称形式中成功合成了arborisidine.
- 两个具有挑战性的四级碳中心的高效建造.
- 证明了复杂的二烯中间体的特定区域功能.
结论:
- 开发的合成途径是不同的和高效的.
- 该战略克服了在光学上活跃的aza-quaternary中心的难题.
- 这项工作为进一步研究Kopsia类提供了宝贵的基础.
相关概念视频
Dehydration Synthesis
149.1K
Overview
Dehydration synthesis (also called a condensation reaction) is the chemical process in which two molecules covalently link together to form a new molecule, along with the release of a water molecule. Many physiologically important compounds form by dehydration synthesis reactions, such as complex carbohydrates, proteins, DNA, and RNA.
Synthesis of carbohydrates
Sugar molecules are covalently linked together by dehydration synthesis. During the reaction, the hydroxyl (-OH) group from...
Dehydration synthesis (also called a condensation reaction) is the chemical process in which two molecules covalently link together to form a new molecule, along with the release of a water molecule. Many physiologically important compounds form by dehydration synthesis reactions, such as complex carbohydrates, proteins, DNA, and RNA.
Synthesis of carbohydrates
Sugar molecules are covalently linked together by dehydration synthesis. During the reaction, the hydroxyl (-OH) group from...
149.1K
Synthesis and Decomposition Reactions
38.1K
Synthesis and decomposition are two types of redox reactions. Synthesis means to make something, whereas decomposition means to break something. The reactions are accompanied by chemical and energy changes.
38.1K
Lagging Strand Synthesis
61.0K
During replication, the complementary strands in double-stranded DNA are synthesized at different rates. Replication first begins on the leading strand. Replication starts later, occurs more slowly, and proceeds discontinuously on the lagging strand.
There are several major differences between synthesis of the leading strand and synthesis of the lagging strand. 1) Leading strand synthesis happens in the direction of replication fork opening, whereas lagging strand synthesis happens in the...
There are several major differences between synthesis of the leading strand and synthesis of the lagging strand. 1) Leading strand synthesis happens in the direction of replication fork opening, whereas lagging strand synthesis happens in the...
61.0K
Transfer RNA Synthesis
13.3K
One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
13.3K
Total Voids in Concrete
473
Total voids in concrete encompass gel water volume, capillary pores, and entrapped air. Gel water (retained within the cement hydration products) and physically entrapped or adsorbed water are significant for the hydration process. For complete hydration, it's estimated that the space needed for the products of a cubic centimeter of cement doubles. Capillary pores constitute the unoccupied space within the hydrated cement paste, with their size largely influenced by the water-to-cement...
473
Total Internal Reflection Fluorescence Microscopy
11.1K
Total internal reflection fluorescence microscopy or TIRF is an advanced microscopic technique used to visualize fluorophores in samples close to a solid surface with a higher refractive index, such as a glass coverslip. TIRF only allows fluorophores in proximity to the solid surface to be excited. When light from a medium with a lower refractive index (such as air) hits the glass coverslip at a critical angle, the light undergoes total internal reflection stead of passing through the glass.
11.1K

