- Synthesis and biological evaluation of 12-, 13-, 14-membered macrolides and open chain 2,6-trans-disubstituted dihydropyran analogues for aspergillides
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Stereoselective synthesis of twenty (three 12-, five 13- and twelve 14-membered) macrolides and seventeen functionalized 2,6-trans-disubstituted dihydropyran derivatives have been achieved. The key reactions include an Achmatowicz rearrangement, Ferrier-type alkynylation, Yamaguchi macrolactonization and Lindlar's hydrogenation. Biological screening of the synthesised compounds showed moderate activity against human cancer cell-lines.
- Pabbaraja, Srihari,Gantasala, Naresh,Ydhyam, Sridhar,Namballa, Hari Krishna,Gundeboina, Subhashini,Lambu, Mallikharjuna R.,Meena, Sanjeev,Datta, Dipak
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p. 2570 - 2576
(2018/05/30)
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- Total Synthesis of Chaetoglobin A via Catalytic, Atroposelective Oxidative Phenol Coupling
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The first total synthesis of chaetoglobin A (1), which features a chiral axis between two identical highly oxygenated bicyclic cores, was successfully completed in 12 steps from 2,6-dimethoxytoluene. Vanadium-catalyzed oxidative phenol coupling, as a key
- Kang, Houng,Torruellas, Carilyn,Liu, Jinchu,Kozlowski, Marisa C.
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p. 5554 - 5558
(2018/09/29)
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- Total synthesis of (+)-brefeldin a
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(+)-Brefeldin A was synthesized through an efficient route, which features (1) construction of the five-membered ring from a Crimmins aldol via tandem Li-I exchange and carbanion-mediated cyclization with concurrent removal of the chiral auxiliary, (2) introduction of the lower side chain (C10 to C16) via a Rh-catalyzed Michael addition of a vinyl boronic acid, (3) stereoselective reduction of the C7 ketone with Sml2, and (4) a 2-methyl-6- nitrobenzoic anhydride-mediated (Shiina) lactonization.
- Wu, Yikang,Gao, Jian
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supporting information; experimental part
p. 1533 - 1536
(2009/04/12)
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- Enantioselective esterifications of unsaturated alcohols mediated by a lipase prepared from Pseudomonas sp.
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Competition experiments and measurements of enantioselectivities were used to develop a simple active-site model (Figure 1) for resolutions of β-hydroxy-α-methylene carbonyl compounds III via acyl transfers mediated by lipase from Pseudomonas sp. (AK). Further experiments were used to test and refine this model with respect to resolutions of allylic, propargylic, homopropargylic, and other alcohols (Tables I-IV, respectively). The model proved extremely reliable for predicting the sense of the asymmetric induction, and the combined data collected in this paper give an indication of what structural features of the substrates can be correlated with high enantioselectivities in these resolutions. Furthermore, the results account for the conspicuous reversal of enantioselectivity previously observed in resolutions of γ-hydroxy-α,β-unsaturated esters 35. Kinetic resolutions of two substrates (allenol 14 and dienol 9) via asymmetric epoxidations were performed for comparison with the methodology presented in this paper.
- Burgess, Kevin,Jennings, Lee D.
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p. 6129 - 6139
(2007/10/02)
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- Facile synthesis of (+)-Brefeldin A
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(+)-Brefeldin A (1) was synthesized by using (+)-4-cyanomethylcyclopent-2-en-1-one (2) as a key compound. 4-Hydroxy-2-enoate functionality was built by the reaction of the aldehyde (7) with (S)-ethyl p-chlorophenylsulfinylacetate.
- Nokami,Ohkura,Dan-Oh,Sakamoto
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p. 2409 - 1412
(2007/10/02)
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- Synthesis of Z,Z-Skipped Diene Macrolide Pheromones for Cryptolestes and Oryzaephilus Grain Beetles (Coleoptera Cucujidae)
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Three macrolide aggregation pheromones for Cryptolestes pusillus, Cryptolestes turcicus, and Oryzaephilus mercator were synthesized stereoselectively from acyclic precursors.The first, 13-methyl-(5Z,8Z)-tridecadienolide (I), is an aggregation pheromone for C. turcicus and had been tentatively identified previously in Phoracantha synonyma.The second, 11-methyl-(3Z,6Z)-undecadienolide (II), is an aggregation pheromone for O. mercator.The third, (3Z,6Z)-dodecadienolide (III) is an aggregation pheromone for O. mercator and is also slightly attractive to C. pusillus.The racemic and enantiomeric forms of I were synthesized.
- Millar, Jocelyn G.,Oehlschlager, Allan C.
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p. 2332 - 2338
(2007/10/02)
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