- Asymmetric total synthesis of four stereoisomers of the sex pheromone of the western corn rootworm
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A convergent synthesis of four stereoisomers of the sex pheromone of the western corn rootworm (8-methyldecan-2-yl propionate, 1) from commercially available chiral starting materials is reported. The key step was Julia–Kocienski olefination between chiral BT-sulfone and chiral aldehyde. This synthetic route provided the four stereoisomers of 1 in 24–29% total yield via a six-step sequence. The simple scale-up strategy provides a new way to achieve the asymmetric synthesis of the sex pheromone.
- Sun, Zhi-Feng,Zhang, Tao,Liu, Jinyang,Du, Zhen-Ting,Zheng, Huaiji
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- Synthesis method and application of diabrotica virgifera virgifera le conte sex pheromone
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The invention belongs to the technical field of pesticide chemistry, and discloses a synthesis method and application of diabrotica virgifera virgifera le conte sex pheromone. The synthesis method comprises the steps of enabling chiral sulfone compounds, i.e., (S)-2-methylbutyl thiazolsulfone and (R)-2-methylbutyl thiazolsulfone to be respectively subjected to a Julia-Kocienski coupling reaction with chiral aldehyde compounds, i.e., (S)-6-aldehyde hexan-2-ol propionate and (R)-6-aldehyde hexan-2-ol propionate, and carrying out hydrogenation reduction on the product of the coupling reaction soas to obtain the diabrotica virgifera virgifera le conte sex pheromone. In addition, the diabrotica virgifera virgifera le conte sex pheromone prepared by the method can be applied to the prevention and control of diabrotica virgifera virgifera le conte. The synthetic route of the diabrotica virgifera virgifera le conte sex pheromone is simplified, fewer by-products are produced in the reaction, and the reaction yield is greatly increased.
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Paragraph 0072; 0092; 0102-0103
(2018/07/15)
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- Stereoselective synthesis of the Paulownia bagworm sex pheromone
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According to our retrosynthesis, the main chain of the target molecule could be constructed using a C5?+?C7?+?C5 strategy. The key induction reaction afforded chiral methyl group moieties using different Evans templates with different configurations. Li2CuCl4 was effectively employed in the Csp3[sbnd]Csp3 coupling protocol. The target molecular was obtained in a 12.6% overall yield with nine steps in the longest linear route.
- Sun, Zhi-Feng,Zhou, Lu-Nan,Zhang, Tao,Du, Zhen-Ting
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p. 558 - 562
(2017/06/19)
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- Polyunsaturated C-Glycosidic 4-Hydroxy-2-pyrone Derivatives: Total Synthesis Shows that Putative Orevactaene Is Likely Identical with Epipyrone A
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Orevactaene and epipyrone A were previously thought to comprise the same polyunsaturated tail but notably different C-glycosylated 4-hydroxy-2-pyrone head groups. Total synthesis now shows that the signature bicyclic framework assigned to orevactaene is a chimera; the compound is almost certainly identical with epipyrone A, whose previously unknown stereochemistry has also been established during this study. Key to success was the ready formation of the bicyclic core of putative orevactaene by a sequence of two alkyne cycloisomerization reactions using tungsten and gold catalysis. Equally important was the flexibility in the assembly process gained by the use of heterobimetallic polyunsaturated modules whose termini could be selectively and consecutively addressed in a practical one-pot cross-coupling sequence.
- Preindl, Johannes,Schulthoff, Saskia,Wirtz, Conny,Lingnau, Julia,Fürstner, Alois
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supporting information
p. 7525 - 7530
(2017/06/13)
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- Rational Design of Thermodynamic and Kinetic Binding Profiles by Optimizing Surface Water Networks Coating Protein-Bound Ligands
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A previously studied congeneric series of thermolysin inhibitors addressing the solvent-accessible S2′ pocket with different hydrophobic substituents showed modulations of the surface water layers coating the protein-bound inhibitors. Increasing stabilization of water molecules resulted in an enthalpically more favorable binding signature, overall enhancing affinity. Based on this observation, we optimized the series by designing tailored P2′ substituents to improve and further stabilize the surface water network. MD simulations were applied to predict the putative water pattern around the bound ligands. Subsequently, the inhibitors were synthesized and characterized by high-resolution crystallography, microcalorimetry, and surface plasmon resonance. One of the designed inhibitors established the most pronounced water network of all inhibitors tested so far, composed of several fused water polygons, and showed 50-fold affinity enhancement with respect to the original methylated parent ligand. Notably, the inhibitor forming the most perfect water network also showed significantly prolonged residence time compared to the other tested inhibitors.
- Krimmer, Stefan G.,Cramer, Jonathan,Betz, Michael,Fridh, Veronica,Karlsson, Robert,Heine, Andreas,Klebe, Gerhard
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p. 10530 - 10548
(2016/12/16)
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- Studies on tridecaptin B1, a lipopeptide with activity against multidrug resistant Gram-negative bacteria
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Previously other groups had reported that Paenibacillus polymyxa NRRL B-30507 produces SRCAM 37, a type IIA bacteriocin with antimicrobial activity against Campylobacter jejuni. Genome sequencing and isolation of antimicrobial compounds from this P. polymyxa strain show that the antimicrobial activity is due to polymyxins and tridecaptin B1. The complete structural assignment, synthesis, and antimicrobial profile of tridecaptin B1 is reported, as well as the putative gene cluster responsible for its biosynthesis. This peptide displays strong activity against multidrug resistant Gram-negative bacteria, a finding that is timely to the current problem of antibiotic resistance.
- Cochrane, Stephen A.,Lohans, Christopher T.,Van Belkum, Marco J.,Bels, Manon A.,Vederas, John C.
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supporting information
p. 6073 - 6081
(2015/06/08)
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- Directed orthometalation and the asymmetric total synthesis of N -deoxymilitarinone A and torrubiellone B
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A diverted total synthesis (DTS) approach to the total synthesis of pyridone alkaloids N-deoxymilitarinone A (8) and torrubiellone B (10) has been developed. The common intermediate 14 was first assembled by a dual directed orthometalation process using a methoxymethyl group as directed metalation group. Other crucial steps include the assembly of polyenes under aldol condensation for DTS using general and concise strategy and diastereoselective synthesis of the syn-dimethyl array by an Evans aldol reaction.
- Ding, Feiqing,William, Ronny,Leow, Min Li,Chai, Hua,Fong, Jacqueline Zi Mei,Liu, Xue-Wei
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supporting information
p. 26 - 29
(2014/01/23)
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- Collective synthesis of 4-hydroxy-2-pyridone alkaloids and their antiproliferation activities
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A collective synthesis of 4-hydroxy-2-pyridone alkaloids - specifically, pretenellin B, prebassianin B, farinosone A, militarione D, pyridovericin, and torrubiellone C - has been achieved. Key steps include using a strategic convergent method to synthesize the densely substituted pyridone key intermediate by Suzuki-Miyaura cross-coupling reaction, a divergent synthesis approach of target molecules by aldol condensation of pyridone intermediate with homologous aldehydes, and an iterative synthesis of homologous aldehydes with all-trans-polyene backbones. Interestingly, among the six tumor cell lines investigated, torrubiellone C was found to induce potent and apoptotic inhibitory activities on Jurkat T cells with IC50 values of 7.05 μM. Hence, this approach could potentially contribute to the synthesis of bioactive small-molecule libraries as well as drug discovery.
- Ding, Feiqing,Leow, Min Li,Ma, Jimei,William, Ronny,Liao, Hongze,Liu, Xue-Wei
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supporting information
p. 2548 - 2554
(2014/10/15)
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- Asymmetric synthesis and absolute configuration of streptophenazine G
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The asymmetric synthesis of the antibacterial natural product, streptophenazine G, has been achieved by employing asymmetric alkylation and asymmetric aldol reactions using chiral oxazolidinones as the key steps. The originally proposed structure for streptophenazine G has been revised, and its absolute configuration has been determined to be 1′S,2′R,6′S. The asymmetric total synthesis of 6′-epi-streptophenazine G is also described.
- Yang, Zhicai,Jin, Xiaomin,Guaciaro, Michael,Molino, Bruce F.
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experimental part
p. 3191 - 3196
(2012/05/19)
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