2277-16-9Relevant academic research and scientific papers
Stereoselective synthesis of the C17–C29 fragment of amphidinolide N
Fujishima, Yuki,Ogura, Yusuke,Towada, Ryo,Enomoto, Masaru,Kuwahara, Shigefumi
, p. 5240 - 5242 (2016)
An enantio- and diastereoselective synthesis of the C17–C29 fragment of amphidinolide N, an extremely potent macrocyclic cytotoxin of marine origin, has been accomplished from a known olefinic ester by a 10-step sequence that involves a ring opening of a chiral epoxide with a dithiane derivative to construct the full carbon skeleton, a highly diastereoselective reduction of a β-hydroxy ketone intermediate to install the C21 asymmetric center, and a one-pot Sharpless AD/cyclization sequence to form a trans-substituted tetrahydrofuran ring system.
Expanding the Biocatalytic Toolbox with a New Type of ene/yne-Reductase from Cyclocybe aegerita
Karrer, Dominik,Gand, Martin,Rühl, Martin
, p. 2191 - 2199 (2021/02/26)
This study introduces a new type of ene/yne-reductase from Cyclocybe aegerita with a broad substrate scope including aliphatic and aromatic alkenes/alkynes from which aliphatic C8-alkenones, C8-alkenals and aromatic nitroalkenes were the preferred substrates. By comparing alkenes and alkynes, a ～2-fold lower conversion towards alkynes was observed. Furthermore, it could be shown that the alkyne reduction proceeds via a slow reduction of the alkyne to the alkene followed by a rapid reduction to the corresponding alkane. An accumulation of the alkene was not observed. Moreover, a regioselective reduction of the double bond in α,β-position of α,β,γ,δ-unsaturated alkenals took place. This as well as the first biocatalytic reduction of different aliphatic and aromatic alkynes to alkanes underlines the novelty of this biocatalyst. Thus with this study on the new ene-reductase CaeEnR1, a promising substrate scope is disclosed that describes conceivably a broad occurrence of such reactions within the chemical landscape.
Easy access to aroma active unsaturated γ-lactones by addition of modified titanium homoenolate to aldehydes
Frerot, Eric,Bagnoud, Alain
experimental part, p. 4057 - 4061 (2011/10/31)
The homo-Reformatsky reaction, in which a metal homoenolate of an ester is added to an aldehyde, was adapted to produce γ-lactones from unsaturated, enolizable aldehydes. By use of titanium homoenolate, 11 different γ-lactones were synthesized in one step with moderate to good yields from readily available aldehydes. In particular, this procedure allowed the rapid preparation of a series of C12 unsaturated γ-lactones differing in the position and configuration of the double bond. These reference compounds will be used to identify previously unknown lactones in butter oil. The chromatographic, spectral, and sensory descriptions of the synthesized lactones are provided.
Metalloporphyrin Cr(TPP)Cl-catalyzed Claisen rearrangement of simple aliphatic allyl vinyl ethers and its unique stereoselectivity
Takanami, Toshikatsu,Hayashi, Mikiko,Suda, Kohji
, p. 2893 - 2896 (2007/10/03)
The catalytic Z-selective Claisen rearrangement of simple aliphatic allyl vinyl ethers can be achieved using a chromium(III) porphyrin complex, Cr(TPP)Cl, as a catalyst: Cr(TPP)Cl significantly enhances reversal of E-Z selectivity in the thermal Claisen r
Synergistic sex pheromone components of white-spotted tussock moth, Orgyia thyellina
Gries, Gerhard,Clearwater, John,Gries, Regine,Khaskin, Grigori,King, Skip,Schaefer, Paul
, p. 1091 - 1104 (2007/10/03)
In 1996, the exotic white-spotted tussock moth (WSTM), Orgyia thyellina (Lepidoptera: Lymantriidae), was discovered in Auckland, New Zealand. Because establishment of WSTM would threaten New Zealand's orchard industry and international trade, eradication of WSTM with microbial insecticide was initiated. To monitor and complement eradication of WSTM by capture of male moths in pheromone-baited traps, pheromone components of female WSTM needed to be identified. Coupled gas chromatographic-electroantennographic detection analysis of pheromone gland extract revealed several compounds that elicited responses from male moth antennae. Mass spectra of the two most EAD-active compounds suggested, and comparative GC-MS of authentic standards confirmed, that they were (Z)-6-heneicosen-11-one (Z6-11-one) and (Z)-6-heneicosen-9- one, the latter termed here 'thyellinone.' In field experiments in Japan, Z6- 11-one plus thyellinone at a 100:5 ratio attracted WSTM males, whereas either ketone alone failed to attract a single male moth. Addition of further candidate pheromone components did not enhance attractiveness of the binary blend. Through the 1997-1998 summer, 45,000 commercial trap lures baited with 2000 μg of Z6-11-one and 100 μg of thyellinone were deployed in Auckland towards eradication of the residual WSTM population.
Insect pheromones and their analogs. LVIII. Synthesis of hexadeca-7Z,11E-dien-1-yl acetate - A component of the sex pheromones of Pectinophora gossypiella and Sitotroga cerealella
Odinokov,Vakhidov,Shakhmaev,Zorin
, p. 186 - 188 (2007/10/03)
A new synthesis of hexadeca-7Z,11E-dien-1-yl acetate - a component of the sex pheromones of the pink bollworm (Pectinophora gossypiella) and the Angoumois grain moth (Sitotroga cerealella) - is proposed that is based on a thermal Claisen rearrangement. Scientific-Research Institute of Small-Tonnage Chemical Products and Reagents, Ufa, fax 8-(3472) 43 17 31.
SYNTHESIS OF 3E-TETRADECENOL, 3E,9E-TETRADECADIENOL, AND THEIR ACETATES STARTING FROM ACETYLCYCLOPROPANE
Ivanova, N. M.,Cheskis, B. A.,Rubanova, E. V.,Yatsynin, V. G.,Moiseenkov, A. M.,Nefedov, O. M.
, p. 557 - 561 (2007/10/02)
Stereospecific synthesis of the linear E-olefins mentioned in the title was realized by a general scheme that was worked out earlier by the authors and which includes as key step homologization of the corresponding aliphatic pentakisnoraldehydes by means of trimethylsilyloxyvinylcyclopropane and ZnBr2-initiated rearrangement of the intermediate cyclopropylcarbinols under the influence of Me3SiBr.
PALLADIUM-CATALYSED REACTION OF VINYLIC HALIDES WITH PRIMARY ALLYLIC ALCOHOLS: REGIO AND STEREOCONTROLLED SYNTHESIS OF 4-ENALS.
Jeffery, Tuyet
, p. 6641 - 6644 (2007/10/02)
Stereodefined γ,δ-unsaturated aldehydes can be prepared with high regio and stereocontrol by palladium-catalysed coupling of vinylic halides with primary allylic alcohols, in the presence of silver carbonate and tetra-n-butylammonium hydrogen sulphate.
ALIPHATIC CLAISEN REARRANGEMENT PROMOTED BY ORGANOALUMINIUM REAGENTS.
Takai,Mori,Oshima,Nozaki
, p. 446 - 451 (2007/10/02)
Organoaluminium compounds, R//3Al, promote the Claisen rearrangement of allyl vinyl ether derivatives at room temperature under transfer of R or H as a nucleophile to the aldehydic carbon. Treatment of 1-butyl-2-propenyl vinyl ether with a hexane solution of Me//3Al (1. 0 M, 2. 2 equiv) in CH//2ClCH//2Cl at 25 degree C afforded 5-decen-2-ol (91% yield, E/Z equals 47/53), which was produced by the left bracket 3,3 right bracket sigmatropic rearrangement and successive methylation. The rearrangements with alkynylation, alkenylation, and hydrogenation are also achieved. The regular Claisen rearrangement products, of gamma , delta -unsaturated aldehydes (ketones), are obtained at 25 degree C in good to excellent yields with Et//2AlSPh (2. 5 equiv) or the combination of Et//2AlCl (2. 0 euiv) and PPh//3 (2. 2 equiv).
