88557-54-4Relevant academic research and scientific papers
Synthesis of (25R)-cholest-5-ene-3β,26-diol and its radiolabeled analog
D'Ambra, Thomas E.,Javitt, Norman B.,Nakanishi, Koji,Warchol, Tadeusz
, p. 3801 - 3804 (1997)
A new, convenient and stereoselective route to the synthesis of (25R)-cholest-5-ene-3β,26-diol (1) and its radiolabeled analog 4 is described. The key step is a Julia condensation of sulfone 6 with aldehyde 12 to furnish compound 13. Further reduction of
Synthesis of the C6-C16 polyene fragment of ratjadone, a potent cytotoxic metabolite from Sorangium cellulosum
Claus, Eckhard,Kalesse, Markus
, p. 4157 - 4160 (1999)
The Pd-catalyzed synthesis of the polyene fragment of ratjadone is described. This strategy employs the Stille-coupling for the coupling of the tetrahydropyran subunit and the Suzuki coupling for attaching the unsaturated lactone to the polyene chain.
Total synthesis of four stereoisomers of methyl 4,8,12-trimethylpentadecanoate, a major component of the sex pheromone of the stink bug: Edessa meditabunda
Schulz, Stefan,Szczerbowski, Daiane,Zarbin, Paulo Henrique Gorgatti
, p. 5034 - 5044 (2020/07/30)
The male-produced sex pheromone of the stink bug Edessa meditabunda was previously identified as a mixture of the esters methyl 4,8,12-trimethylpentadecanoate (1) and methyl 4,8,12-trimethyltetradecanoate (2), produced in a ratio of 92 : 8, respectively.
Asymmetric syntheses of potential anti-malarial drugs designed from Fieser's 2-hydroxy-3-(2-methyloctyl)naphthalene-1,4-dione
Fisher, Louise M.,Kim, Eliana E.,Moskalev, Nicolai V.,Gribble, Gordon W.
, p. 56 - 66 (2020/10/02)
We describe asymmetric syntheses of the potential anti-malarial drugs (S)-2-(8-fluoro-2-methyloctyl)-3-hydroxynaphthalene-1,4-dione, (S)-2-hydroxy-3-(8-trifluoromethyl-2-methyloctyl)-3-hydroxynaphthalene-1,4-dione, and (S)-2-hydroxy-3-(2-methyloctyl)naphthalene-1,4-dione, which are patterned after Fieser's “10576,” known to be active against the mosquito borne parasite Plasmodium falciparum.
Enantioselective Synthesis and Activity of All Diastereoisomers of (E)-Phytal, a Pheromone Component of the Moroccan Locust, Dociostaurus maroccanus
Guerrero, Angel,Ramos, Victoria Elena,López, Sergio,Alvarez, José María,Domínguez, Aroa,Coca-Abia, María Milagro,Bosch, María Pilar,Quero, Carmen
, p. 72 - 80 (2019/01/15)
The Moroccan locust, Dociostaurus maroccanus (Thunberg, 1815) (Orthoptera: Acrididae), is a polyphagous pest capable of inflicting large losses in agriculture under favorable environmental and climatic conditions. Currently, control of the pest relies solely on the application of conventional insecticides that have negative effects on the environment and human safety. In the search for a more rational, environmentally acceptable approach for locust control, we have previously reported that (Z/E)-phytal (1) is a male-produced candidate sex pheromone of this acridid. This molecule, with two stereogenic centers at C-7 and C-11, has four different diastereomers along with the Z/E stereochemistry of the double bond at C-2. In this paper, we present for the first time the enantioselective synthesis of the four diastereomers of (E)-phytal and their electrophysiological and behavioral activity on males and females. Our results demonstrate that the (R,R)-phytal is the most active diastereomer in both assays, significantly attracting females in a double-choice Y olfactometer, and confirming the previous chromatographic assignment as component of the sex pheromone of the Moroccan locust.
Strictly Alternating Sequences When Copolymerizing Racemic and Chiral Acetylene Monomers with an Organo-Rhodium Catalyst
Yoshida, Yoshiaki,Mawatari, Yasuteru,Sasaki, Takahiro,Hiraoki, Toshifumi,Wagner, Manfred,Müllen, Klaus,Tabata, Masayoshi
, p. 1291 - 1301 (2017/03/09)
A racemic mixture and two chiral monomers of 2-methyl-1-butyl propiolate, i.e., rac1, R1, and S1, were stereoregularly polymerized with a catalyst, [Rh(norbornadiene)Cl]2, in methanol at 40 °C to obtain the corresponding helical racemic and two chiral polymers, Prac1, PR1, and PS1, and a copolymer, Pco. The 1H and 13C NMR spectra of the racemic and chiral polymers differed, although the NMR spectra of their monomers were the same. The structures of the Pco copolymers with different chiral monomer ratios were analyzed using 1D and 2D NMR, optical rotation, circular dichroism (CD), UV-vis, and computational methods to elucidate the stereochemical effect of the chiral monomers together with the polymerization mechanism. The temperature dependence of 1H and 13C NMR spectra in line shape and intensity indicated that the helical main chain undergoes restricted rotation around the ester methylene bonds ?O-CH2- through a three-site jump exchange called an accordion-like helix oscillation (HELIOS). The energetically preferred structures of the helical-sense polymers PR1 or PS1 were simulated using the MMFF94 program. The dependence of the NMR spectral line shapes, optical rotations, and calculated structures on the monomer feed clearly indicated that the copolymers alternatively incorporate R1 and S1 to generate one-handed helical-sense chains. Based on these results, a polymerization mechanism is proposed, explaining a strictly alternating copolymerization that yields helical chains.
Isolation, structural elucidation, and biosynthesis of 15-norlankamycin derivatives produced by a type-II thioesterase disruptant of Streptomyces rochei
Arakawa, Kenji,Cao, Zhisheng,Suzuki, Natsumi,Kinashi, Haruyasu
supporting information; experimental part, p. 5199 - 5205 (2011/08/06)
Lankamycin, a 14-membered macrolide antibiotic, contains a 3-hydroxy-2-butyl side chain at C-13. To analyze the function of lkmE, which encodes type-II thioesterase in the lankamycin cluster, we carried out a gene disruption experiment. Disruption of lkmE
Hierarchical chiral expression from the nano- to mesoscale in synthetic supramolecular helical fibers of a nonamphiphilic C 3-symmetrical π-functional molecule
Danila, Ion,Riobe, Francois,Piron, Flavia,Puigmarti-Luis, Josep,Wallis, John D.,Linares, Mathieu,Agren, Hans,Beljonne, David,Amabilino, David B.,Avarvari, Narcis
, p. 8344 - 8353 (2011/07/08)
The controlled preparation of chiral structures is a contemporary challenge for supramolecular science because of the interesting properties that can arise from the resulting materials, and here we show that a synthetic nonamphiphilic C3 compound containing π-functional tetrathiafulvalene units can form this kind of object. We describe the synthesis, characterization, and self-assembly properties in solution and in the solid state of the enantiopure materials. Circular dichroism (CD) measurements show optical activity resulting from the presence of twisted stacks of preferential helicity and also reveal the critical importance of fiber nucleation in their formation. Molecular mechanics (MM) and molecular dynamics (MD) simulations combined with CD theoretical calculations demonstrate that the (S) enantiomer provides the (M) helix, which is more stable than the (P) helix for this enantiomer. This relationship is for the first time established in this family of C3 symmetric compounds. In addition, we show that introduction of the wrong enantiomer in a stack decreases the helical reversal barrier in a nonlinear manner, which very probably accounts for the absence of a majority rules effect. Mesoscopic chiral fibers, which show inverted helicity, i.e. (P) for the (S) enantiomer and (M) for the (R) one, have been obtained upon reprecipitation from dioxane and analyzed by optical and electronic microscopy. The fibers obtained with the racemic mixture present, as a remarkable feature, opposite homochiral domains within the same fiber, separated by points of helical reversal. Their formation can be explained through an oscillating crystallization mechanism. Although C3 symmetric disk-shaped molecules containing a central benzene core substituted in the 1,3,5 positions with 3,3′-diamido-2,2′-bipyridine based wedges have shown peculiar self-assembly properties for amphiphilic derivatives, the present result shows the benefits of reducing the nonfunctional part of the molecule, in our case with short chiral isopentyl chains. The research reported herein represents an important step toward the preparation of functional mesostructures with controlled helical architectures.
Identification of (S)-11-cycloheptyl-4-methylundecanoic acid in acylphosphatidylglycerol from Alicyclobacillus acidoterrestris
Rezanka, Tomas,Siristova, Lucie,Melzoch, Karel,Sigler, Karel
experimental part, p. 104 - 113 (2010/03/03)
A method is described for the identification of molecular species of acylphosphatidylglycerols containing a branched cyclo fatty acid ((S)-11-cycloheptyl-4-methylundecanoic acid; brc19:0) from Alicyclobacillus acidoterrestris and its identification as picolinyl ester by means of GC-MS. The combination of TLC, negative RP-HPLC-ESI-MS/MS, enzymatic hydrolysis, and GC-MS was used to identify unusual molecular species of acylphosphatidylglycerols with cyclic and branched FA. The acid, brc19:0, was also synthesized to unambiguously confirm its structure. According to feeding experiments with 13C-labeled propionate, the C3 internal unit (branched methyl) of brc19:0 is assembled from propionate and not from methionine.
Synthesis of all the stereoisomers of 6-methyl-2-octadecanone, 6,14-dimethyl-2-octadecanone, and 14-methyl-2-octadecanone, the components of the female-produced sex pheromone of a moth, Lyclene dharma dharma
Mori, Kenji
scheme or table, p. 2798 - 2805 (2009/08/15)
All of the stereoisomers of the components of the female-produced sex pheromone of a moth, Lyclene dharma dharma, were synthesized. They are (R)- and (S)-6-methyl-2-octadecanone, (6R,14R)-, (6R,14S)-, (6S,14R)-, and (6S,14S)-6,14-dimethyl-2-octadecanone, and (R)- and (S)-14-methyl-2-octadecanone. Enantiomers of citronellal and methyl (S)-3-hydroxy-2-methylpropanoate were the starting materials, and olefin cross metathesis was employed as the key reaction.
