Synthesis of the tetracyclic ABCE ring subunit I, bearing the 13-membered azacycle, of manzamine A
摘要:
The tetracyclic ABCE ring, which bears the crucial 13-membered azacycle, of manzamine A has been synthesized through the corresponding bicyclic BC ring subunit as a promising synthetic intermediate. (C) 1998 Elsevier Science Ltd. All rights reserved.
New Metal-Free One-Pot Synthesis of Substituted Allenes from Enones
作者:Meng Tang、Chun-An Fan、Fu-Min Zhang、Yong-Qiang Tu、Wen-Xue Zhang、Ai-Xia Wang
DOI:10.1021/ol802445p
日期:2008.12.18
A new metal-free, one-pot synthesis of substituted allenes from enones was discovered for the first time, in which a tertiary amine as a base was found to be an effective promoter in such novel transformations. The present synthetic protocol proceeded readily with high compatibility of sensitive functional groups, and it provides a new efficient way to access a series of synthetically important allenes
Amphimic acids and related long-chain fatty acids as DNA topoisomerase I inhibitors from an Australian sponge, Amphimedon sp.: Isolation, structure, synthesis, and biological evaluation
fatty acids have been isolated from an Australian sponge, Amphimedon sp., as human DNA topoisomerase Iinhibitors. Three of them, amphimic acids A (1)-C (3), are unusual fatty acids possessing a cyclopropylidene group, and one is a new C30 fatty acid 4. Their structures were elucidated by spectroscopic analysis and chemical degradation. The enantioselective synthesis of 1 was carried out to determine
从澳大利亚海绵Amphimedon sp。中分离出了几种C 27 – C 30不饱和脂肪酸,作为人类DNA拓扑异构酶I抑制剂。其中三个,两性酸A(1)-C(3),是具有环亚丙基的不常见脂肪酸,一个是新的C 30脂肪酸4。通过光谱分析和化学降解阐明了它们的结构。进行1的对映选择性合成以确定两性酸的绝对构型。对这些天然产物和合成衍生物评估了DNA拓扑异构酶I的抑制活性。
Syntheses and Biological Activities of Danicalipin A Derivatives
作者:Taiki Umezawa、Takeshi Maeda、Takuya Akiyama、Nurcahyo Iman Prakoso、Jakia Jerin Mehjabin、Tatsufumi Okino、Fuyuhiko Matsuda
DOI:10.1002/cbdv.202300400
日期:2023.6
Synthesis of three derivatives of danicalipin A, tetrachloride, trisulfate and a fluorescent probe was achieved through Wittig reaction strategy. Toxicity of the derivatives against brine shrimp (Artemia salina) as also investigated to provide useful information for the biological activity; i) less chloride derivative showed similar toxicity to danicalipin A, ii) the amphiphilic property, a characteristic
通过Wittig反应策略合成了丹卡利平A的三种衍生物、四氯化物、三硫酸盐和荧光探针。还研究了衍生物对丰年虾(Artemia salina)的毒性,为生物活性提供有用的信息;i) 较少的氯化物衍生物表现出与丹尼卡利平 A 相似的毒性,ii) 两亲性(丹尼卡利平 A 的特征)至关重要,因为三硫酸盐显着降低了毒性,以及 iii) 荧光衍生物保留了丹尼卡利平 A 的丰年虾毒性。
A Remarkably Useful Sulfur Bridge as Synthetic Lever in an Approach to Javanicin B
作者:Claude Spino、Amélie Dion
DOI:10.3987/com-16-s(s)58
日期:——
A concise and efficient synthesis of a non-racemic advanced intermediate to the quassinoid javanicin B is disclosed. The strategy is centred on a triple diene-transmissive Diels-Alder cycloaddition to form the four rings of javanicin B. A sulfur bridge plays several crucial roles allowing an intramolecular cycloaddition to occur with complete stereoselectivity, controlling the stereochemical outcome of another cycloaddition, and transforming into a pivotal electrophile for the introduction of a particularly hindered methyl group.
Attempts directed towards the synthesis and determination of the absolute stereochemistry of iso-cladospolide-B and cladospolides-B and C
Attempts to synthesise iso-cladospolide-B, cladospolide-B and cladospolide-C resulted in macrolides 1, 2 and 4 along with butenolide 3. Of the three stereogenic centres, the C-4/C-5 vic-diol was obtained from tartaric acid and D-glucose, while the C-11 stereocentre was created by Jacobsen's method. (c) 2006 Elsevier Ltd. All rights reserved.