共查询到20条相似文献,搜索用时 15 毫秒
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Saiyong Pan Jun Xuan Beiling Gao An Zhu Prof. Dr. Hanfeng Ding 《Angewandte Chemie (International ed. in English)》2015,54(23):6905-6908
A concise and diastereoselective total synthesis of the diterpenoid (±)‐steenkrotin A is described for the first time. The strategy mainly features three key ring formations: 1) a rhodium‐catalyzed O? H bond insertion followed by an intramolecular carbonyl‐ene reaction to build up the tetrahydrofuran subunit; 2) sequential SmI2‐mediated Ueno–Stork and ketyl–olefin cyclizations to construct the [5,7] spirobicyclic skeleton; and 3) an intramolecular aldol condensation/vinylogous retro‐aldol/aldol sequence to form the final six‐membered ring with inversion of the relative configuration at the C7 position. 相似文献
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Hugh Nakamura Dr. Chihiro Tsukano Motohiro Yasui Shinsuke Yokouchi Dr. Masayuki Igarashi Prof. Dr. Yoshiji Takemoto 《Angewandte Chemie (International ed. in English)》2015,54(10):3136-3139
Caprazamycin A has significant antibacterial activity against Mycobacterium tuberculosis (TB). The first total synthesis is herein reported and features a) the scalable preparation of the syn‐β‐hydroxy amino acid with a thiourea‐catalyzed diastereoselective aldol reaction, b) construction of a diazepanone with an unstable fatty‐acid side chain, and c) global deprotection with hydrogenation. This report provides a route for the synthesis of related liponucleoside antibiotics with fatty‐acid side chains. 相似文献
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Keunho Kim Jin Kun Cha Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(29):5334-5336
A stereoselective synthesis of cyathin A3 and cyathin B2 has been achieved by a Prins‐type reaction of a cycloalkenyl cyclopropanol. Particularly noteworthy is the use of a spirocyclobutanone moiety as a convenient scaffold for an efficient ring‐closing metathesis to stereoselectively construct a suitably functionalized seven‐membered ring (see scheme).
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Jianguang Han Xia Li Yong Guan Wenjun Zhao Prof. Dr. William D. Wulff Prof. Dr. Xiaoguang Lei 《Angewandte Chemie (International ed. in English)》2014,53(35):9257-9261
The first enantioselective total syntheses of prenylflavonoid Diels–Alder natural products (?)‐kuwanon I, (+)‐kuwanon J, (?)‐brosimone A, and (?)‐brosimone B have been accomplished from a common intermediate based on a concise synthetic strategy. Key elements of the synthesis include a biosynthesis‐inspired asymmetric Diels–Alder cycloaddition mediated by a chiral ligand/boron Lewis acid, as well as a process involving regioselective Schenck ene reaction, reduction, and dehydration to realize a biomimetic dehydrogenation for generation of the required diene precursor. Furthermore, a remarkable tandem inter‐/intramolecular asymmetric Diels–Alder cycloaddition process was applied for the synthesis of (?)‐brosimone A. 相似文献
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Total Syntheses of Linear Polythiazole/Oxazole Plantazolicin A and Its Biosynthetic Precursor Plantazolicin B 下载免费PDF全文
Dr. Zoe E. Wilson Dr. Sabine Fenner Prof. Steven V. Ley 《Angewandte Chemie (International ed. in English)》2015,54(4):1284-1288
Plantazolicin A, a linear decacyclic natural product, exhibits desirable selective activity against the causative agent of anthrax toxicity. The total synthesis of plantazolicin A and its biosynthetic precursor plantazolicin B was successfully achieved by an efficient, unified, and highly convergent route featuring dicyclizations to form 2,4‐concatenated oxazoles and the mild synthesis of thiazoles from natural amino acids. This report represents the first synthesis of plantazolicin B and includes the first complete characterization data for both natural products. 相似文献
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Jiuzhou Guo Bo Li Weihao Ma Mallesham Pitchakuntla Yanxing Jia 《Angewandte Chemie (International ed. in English)》2020,59(35):15195-15198
A practically useful method for the formation of the highly oxygenated bicyclo[3.2.1]octane ring system through Mn(OAc)3‐mediated radical cyclization of alkynyl ketones was developed, which opens up a new avenue for the total synthesis of a number of highly oxidized diterpenoids. Application of this method enabled the first total synthesis of (?)‐glaucocalyxin A. Other salient features of the synthesis include a highly enantioselective conjugate addition/acylation cascade reaction, a Yamamoto aldol reaction, and an intramolecular Diels–Alder reaction to assemble the A/B ring system. 相似文献
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Zhuliang Zhong Donghui Ma Gaoyuan Zhao Huilin Li Dengyu Xu Dr. Xingang Xie Prof. Dr. Xuegong She 《化学:亚洲杂志》2015,10(12):2599-2603
The first asymmetric total synthesis of kravanhin B has been accomplished with a linear reaction sequence of 13 steps starting from (R)‐(?)‐carvone. The synthesis features an intramolecular aldol cyclization to construct the desired cis‐fused decalin skeleton and an acid‐catalyzed dehydration and olefin isomerization to install the γ‐butenolide ring. 相似文献
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Nakahata T Fujimura S Kuwahara S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(17):4584-4593
Pteridic acid A (1) is a spirocyclic octaketide produced by the phytoepiphytic actinomycete Streptomyces hygroscopicus TP-A0451 and possesses potent plant-growth-promoting activity comparable to that of indole-3-acetic acid. The enantioselective total synthesis of this natural product was achieved by employing the Sn(OTf)(2)-mediated Evans aldol reaction and the Fukuyama acetylenic coupling reaction as the key C--C bond-forming steps producing 1 through a 14-step sequence in 22 % overall yield from a known oxazolidinone derivative. MgBr(2)-mediated equilibration of an anomerically favored spirocyclic intermediate used for the synthesis of 1 brought about partial epimerization of the spirocenter to give the corresponding anomerically disfavored epimer, which was converted into pteridic acid B (11-epi-1), another plant-growth promoter of the same microbial origin. 相似文献
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Yuebao Zhang Qianyou Guo Xianwei Sun Ji Lu Yanjun Cao Qiang Pu Zhiwen Chu Dr. Lu Gao Prof. Dr. Zhenlei Song 《Angewandte Chemie (International ed. in English)》2018,57(4):942-946
Convergent total synthesis of bryostatin 8 has been accomplished by an organosilane‐based strategy. The C ring is constructed stereoselectively through a geminal bis(silane)‐based [1,5]‐Brook rearrangement, and the B ring through geminal bis(silane)‐based Prins cyclization, thus efficiently joining the northern and southern parts of the molecule. 相似文献
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Liang Wang Hengtao Wang Yihang Li Prof. Dr. Pingping Tang 《Angewandte Chemie (International ed. in English)》2015,54(19):5732-5735
The first total syntheses of schilancitrilactones B and C have been accomplished in 17 steps (longest linear sequence) from commercially available materials. Key steps include an intramolecular radical cyclization to provide the seven‐membered ring, late‐stage iodination, and an intermolecular radical addition reaction to complete the total synthesis. 相似文献
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Total Synthesis,Stereochemical Reassignment,and Biological Evaluation of (−)‐Lyngbyaloside B 下载免费PDF全文
Prof. Dr. Haruhiko Fuwa Yuta Okuaki Naoya Yamagata Prof. Dr. Makoto Sasaki 《Angewandte Chemie (International ed. in English)》2015,54(3):868-873
(?)‐Lyngbyaloside B is a 14‐membered macrolide glycoside isolated from the marine cyanobacterium Lyngbya sp. as a cytotoxic substance by Moore and co‐workers. The first total synthesis of (?)‐lyngbyaloside B and the reassignment of its stereostructure is described. The synthesis features an Abiko–Masamune aldol reaction, a vinylogous Mukaiyama aldol reaction, and a macrocyclization involving an acyl ketene intermediate for the construction of the macrocyclic backbone, which contains an acylated tertiary alcohol. The antiproliferative activity of selected compounds against a small panel of human cancer cell lines is also reported. 相似文献