共查询到20条相似文献,搜索用时 15 毫秒
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Naoya Itoh Takashi Iwata Hiromi Sugihara Dr. Fuyuhiko Inagaki Prof. Dr. Chisato Mukai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(26):8665-8672
The total syntheses of four fawcettimine‐related Lycopodium alkaloids, (±)‐fawcettimine, (±)‐fawcettidine, (±)‐lycoposerramine‐Q, and (±)‐lycoflexine, were completed in a highly stereoselective manner. The Pauson–Khand reaction of 4‐methylidene‐6‐siloxyoct‐1‐en‐7‐yne followed by regio‐ and stereoselective hydrogenation led to the short‐step preparation of the bicyclo[4.3.0]nonenone intermediate bearing a methyl group with the required stereochemistry. The subsequent chemical manipulation of the bicyclic compound afforded the 6‐5‐9‐membered tricyclic dioxo compound, which was then transformed into the four targeted alkaloids in an alternative and more efficient fashion. 相似文献
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(±)‐Eusiderin G and (±)‐Eusiderin M were first synthesized from pyrogallol, in which the Claisen Rearrangement was used to afford two important C6‐C3 units. 相似文献
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Dr. Weiwu Ren Dr. Qian Wang Prof. Dr. Jieping Zhu 《Angewandte Chemie (International ed. in English)》2016,55(10):3500-3503
The total synthesis of strictamine has been achieved in nine steps from a known enol triflate. Characteristic features of our approach included: a) creation of a C7 all‐carbon quaternary stereocenter at an early synthetic stage; b) use of an N,N‐dimethyl tertiary amine as a surrogate of the primary amine for the rapid build‐up of a functionalized 2‐azabicyclo[3,3,1]nonan‐9‐one skeleton (achieved by using a reaction sequence of α‐bromination of the ketone, followed by a stereoconvergent intramolecular nucleophilic substitution reaction); and c) a late‐stage construction of the indolenine unit. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(28):8366-8369
The first total synthesis of waihoensene, a tetracyclic diterpene containing an angular triquinane and a six‐membered ring, with four contiguous quaternary carbon atoms, was achieved through the tandem cycloaddition reaction of an allenyl diazo substrate containing a six‐membered ring via trimethylenemethane (TMM) diyl intermediate. 相似文献
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A total synthesis of (±)‐boonein ( 8 ) from bicyclo[2.2.1]ketone 9 is described. Bicyclo[3.2.1]lactone 10 is the key intermediate. 相似文献
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Katsuya Shimomaki Prof. Dr. Hiroyuki Kusama Prof. Dr. Nobuharu Iwasawa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(29):9953-9957
The total synthesis of (±)‐integrifolin has been achieved for the first time through the stereoselective preparation of the bicyclo[5.3.0]decane skeleton based on the tungsten‐catalyzed cyclization of acyclic trienynes under photoirradiation conditions. Further key transformations of the cyclized product are the Tamao oxidation through cyclic silyl ether, the introduction of two oxygen functionalities by the oxidation of the diene and the construction of three exo‐methylene moieties. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(26):7592-7595
The first total synthesis of the hexacyclic indole alkaloid (±)‐corymine is described. Starting from the readily available N‐protected tryptamine, the title compound was achieved in 21 steps in 3.4 % overall yield. Key steps of the synthesis include: a) the addition of a malonate to a 3‐bromooxindole to afford 3,3‐disubstituted oxindole, b) the formation of a 12‐membered cyclic enol ether by intramolecular O‐propargylation, immediately followed by propargyl Claisen rearrangement to provide the α‐allenyl ketone stereospecifically, c) DMDO oxidation to install a hydroxy group in a highly stereoselective manner, and d) the SmI2‐mediated reductive C−O bond cleavage to remove the α‐keto carboxyl group. 相似文献
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Kaerophyllin (1) ,hinokinin (2 )andtheiranalogue isohinokinin (3)belongtothedibenzylbutyrolactone lig nans .Kaerophyllin (1)wasisolatedfromtherootofspot tedcowparsley (ChaerophyllummaculatumWilld .) 1andhinokinin (2 )wasisolatedfromtheheartwoodofLiboce drusformosanaFlorin .2 AccordingtoMacRaeandTow ers ,3afivememberedlactoneringandamethylenedioxylgroupwereimportantstructuralcharacteristicswhichcon tributetotheactivityoflignansasantitumoragents .More over ,anunsaturateddoublebondbetweenC3—… 相似文献
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Shoma Mizutani Kenta Komori Tohru Taniguchi Kenji Monde Kouji Kuramochi Kazunori Tsubaki 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(33):9705-9708
A biomimetic synthesis of naturally occurring lactams rubrobramide, flavipucine, and isoflavipucine is described. The key step is a regioselective Darzens reaction between isobutyl glyoxal and an α‐bromo‐β‐ketoamide. The construction of the core tricyclic ring system of rubrobramide was achieved by a cascade reaction in a single step from an α,β‐epoxy‐γ‐lactam. Furthermore, the absolute configuration of naturally occurring (+)‐rubrobramide was determined by vibrational circular dichroism. (±)‐Flavipucine and (±)‐isoflavipucine were synthesized from an epoxyimide, which was prepared by reaction of isobutyl glyoxal with a protected α‐bromo‐β‐ketoamide. Deprotection of the epoxyimide and formation of the pyridone ring gave (±)‐flavipucine, which was converted into (±)‐isoflavipucine by thermal isomerization. 相似文献
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Zhen‐Ting Du Guo‐Ren Yue An‐Pai Li Jun‐Ying Ma Tong‐Xing Wu Xue‐Gong She Xin‐Fu Pan 《中国化学会会志》2004,51(3):505-508
A facile total synthesis of (±)‐nimbiol 1 has been achieved. In order to decrease the dioxo byproduct 2a , an improved oxidation system of CrO3/H2O/HOAc/NaOAc was used. 相似文献
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Shoma Mizutani Kenta Komori Prof. Dr. Tohru Taniguchi Prof. Dr. Kenji Monde Prof. Dr. Kouji Kuramochi Prof. Dr. Kazunori Tsubaki 《Angewandte Chemie (International ed. in English)》2016,55(33):9553-9556
A biomimetic synthesis of naturally occurring lactams rubrobramide, flavipucine, and isoflavipucine is described. The key step is a regioselective Darzens reaction between isobutyl glyoxal and an α‐bromo‐β‐ketoamide. The construction of the core tricyclic ring system of rubrobramide was achieved by a cascade reaction in a single step from an α,β‐epoxy‐γ‐lactam. Furthermore, the absolute configuration of naturally occurring (+)‐rubrobramide was determined by vibrational circular dichroism. (±)‐Flavipucine and (±)‐isoflavipucine were synthesized from an epoxyimide, which was prepared by reaction of isobutyl glyoxal with a protected α‐bromo‐β‐ketoamide. Deprotection of the epoxyimide and formation of the pyridone ring gave (±)‐flavipucine, which was converted into (±)‐isoflavipucine by thermal isomerization. 相似文献
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Dipl.‐Chem. Patrick J. Gross Prof. Dr. Stefan Bräse 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(42):12660-12667
The antibiotic agent fumimycin has been synthesized for the first time. This natural product was found to inhibit the bacterial peptide deformylase and may represent a lead structure to a class of novel antibacterials. Our synthetic strategy towards fumimycin involved the following steps: Dakin oxidation of an aldehyde functionality, conversion of an oxime through radical fragmentation to form an N‐diphenylphosphoryl group, construction of an α‐trisubstituted amine by 1,2‐addition to a ketimine, a Claisen rearrangement with subsequent transition‐metal‐catalyzed olefin isomerization to install a propenyl chain and final amidation. 相似文献
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