3796-70-1Relevant articles and documents
Ene-Reductase Catalyzed Regio- and Stereoselective 1,4-Mono-Reduction of Pseudoionone to Geranylacetone
Breuer, Michael,Ditrich, Klaus,Glueck, Silvia M.,Kroutil, Wolfgang,Oroz-Guinea, Isabel,Schachtschabel, Doreen,Weingarten, Melanie,Winkler, Christoph K.
, (2021/12/22)
The regio- and stereoselective mono-reduction of a particular C=C bond of conjugated C=C double bonds is a very challenging task. Here the regio- and stereoselective 1,4-reduction of pseudoionone, an α,β,γ,δ-bisunsaturated ketone, was demonstrated to give geranylacetone, an industrially relevant molecule. OYE1 from Saccharomyces pastorianus was identified as the most suitable biocatalyst for this reaction. Elevated substrate concentrations of up to 200 mM were tolerated allowing still to reach excellent conversions (>99 % and 80 % for 100 or 200 mM pseudoionone concentration, respectively). Interestingly, the organic cosolvent often required for substrate solubilization in aqueous buffer can be avoided for pseudoionone when using permeabilized E. coli cells containing the overexpressed enzyme instead of purified enzyme, reaching still >99 % conversion at 100 mM (19.2 g/L) substrate concentration. Performing this reaction at a 0.5 g scale allowed to run the reaction to completion (>99 %) and pure product was isolated with 80 % yield. Additionally, the bis-unsaturated ketone 6-methyl-3,5-heptadien-2-one was transformed under similar conditions giving the floral compound sulcatone with excellent conversion (97 %) and 77 % isolated yield. Finally, the stereoselective reduction of the (E,E)- over the (E,Z)-pseudoionone isomer was enabled by the ene-reductase from Zymomonas mobilis (NCR). Thus, both (E)-geranylacetone and (E,Z)-pseudoionone were obtained with isomeric excess above 60 %.
Synthesis method and method for synthesizing plant alcohol, isoplant alcohol and geranyl geraniol by using intermediate farnesylacetone (by machine translation)
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Paragraph 0061; 0072; 0080-0081, (2020/07/21)
The invention relates to a synthesis method of intermediate farnesyl acetone and a method for synthesizing vitamin E, vitamin K1, vitamin K2 side chain isovegetable alcohol, plant alcohol and geranyl geraniol by using farnesyl acetone, and concretely relates to hydrogenation of 5 - farnesyl -2 - acetone and farnesyl acetone through three Grignard reaction to obtain plant ketone. The farnesyl acetone reacts with the vinyl chloride Grignard reagent to obtain geranyl linalool, the aromatic leaf-based geraniol is rearranged under acid catalysis, or farnesyl acetone is directly reacted with the hydroxyl-protected 2 - chloroethanol Grignard reagent to obtain geraniol. The plant alcohol is reacted with the vinyl chloride Grignard reagent to obtain the plant alcohol, and the plant alcohol is directly reacted with the hydroxyl-protected 2 - chloroethanol Grignard reagent to obtain the plant alcohol. The method has the advantages of cheap and easily available starting materials, short synthetic process steps, low product cost and the like. (by machine translation)
Chemoenzymatic Synthesis of the Antifungal Compound (–)-Pestynol by a Convergent, Sonogashira Construction of the Central Yne-Diene
Borra, Suresh,Kumar, Manoj,McNulty, James,Baidilov, Daler,Hudlicky, Tomas
supporting information, p. 77 - 79 (2018/11/23)
A total synthesis of the fungal-derived natural product pestynol is reported via a convergent chemoenzymatic approach from the readily available precursors geranyl bromide, ethyl acetoacetate, trimethylsilylacetylene, and bromobenzene. Synthetic (–)-pestynol proved to be identical in all respects to the natural material, allowing confirmation of the structure including absolute stereochemistry.
Sesquiterpene Cyclizations inside the Hexameric Resorcinarene Capsule: Total Synthesis of δ-Selinene and Mechanistic Studies
Zhang, Qi,Tiefenbacher, Konrad
, p. 12688 - 12695 (2019/08/12)
The synthesis of terpene natural products remains a challenging task due to the enormous structural diversity in this class of compounds. Synthetic catalysts are unable to reproduce the tail-to-head terpene cyclization of cyclase enzymes, which create this diversity from just a few simple linear terpene substrates. Recently, supramolecular structures have emerged as promising enzyme mimetics. In the present study, the hexameric resorcinarene capsule was utilized as an artificial cyclase to catalyze the cyclization of sesquiterpenes. With the cyclization reaction as the key step, the first total synthesis of the sesquiterpene natural product δ-selinene was achieved. This represents the first total synthesis of a sesquiterpene natural product that is based on the cyclization of a linear terpene precursor inside a supramolecular catalyst. To elucidate the reaction mechanism, detailed kinetic studies and kinetic isotope measurements were performed. Surprisingly, the obtained kinetic data indicated that a rate-limiting encapsulation step is operational in the cyclization of sesquiterpenes.
Total syntheses of parthenolide and its analogues with macrocyclic stereocontrol
Long, Jing,Zhang, Shan-Feng,Wang, Pan-Pan,Zhang, Xue-Mei,Yang, Zhong-Jin,Zhang, Quan,Chen, Yue
supporting information, p. 7098 - 7112 (2014/11/08)
The first total synthesis of parthenolide (1) is described. The key feature of this synthesis is the formation of a 10-membered carbocylic ring by a macrocyclic stereocontrolled Barbier reaction, followed by a photoinduced Z/E isomerization. The biological evaluation of a small library of parthenolide analogues (19, 33, and 34) disclosed a preliminary structure-activity relationship (SAR). The results revealed that the C1, C10 double bond configuration of parthenolide has little or no effect on the activity, and the C6 and C7 configurations of the lactone ring have a moderate impact on the activities against some cancer cell lines.
Design, synthesis and anticancer activity evaluation of diazepinomicin derivatives
Yu, Yongguo,Wu, Jianbo,Lei, Fan,Chen, Lei,Wan, Weili,Hai, Li,Guan, Mei,Wu, Yong
, p. 369 - 373 (2013/07/26)
A series of diazepinomicin derivatives were synthesized and evaluated in vitro for their growth inhibitory activity against the human carcinoma cell lines. The results indicated the anticancer selectivity of this kind of compounds. Based on the results, preliminary structure-activity relationships were discussed.
Synthetic studies towards stachybotrin C
Tumma, Naresh,Jacolot, Maiwenn,Jean, Mickael,Chandrasekhar, Srivari,Van De Weghe, Pierre
, p. 2919 - 2922 (2013/02/22)
The preparation of racemic des-hydroxy stachybotrin C is described. Different approaches have been studied. Observations made in the course of the synthesis show the efficiency of the intermolecular cyclization between the diethyl acetal 19 and phenol 12 leading to the benzopyran moiety 17. Georg Thieme Verlag KG · Stuttgart · New York.
Control of the regio- and diastereoselectivity for the preparation of highly functionalized terpenic cyclopentanes through radical cyclization
Arteaga, Jesus F.,Dieguez, Horacio R.,Gonzalez-Delgado, Jose A.,Quilez Del Moral, Jose F.,Barrero, Alejandro F.
supporting information; experimental part, p. 5002 - 5011 (2011/11/06)
The titanocene-mediated cyclization of suitably functionalized acyclic C10 epoxy-polyprenes leads, with moderate stereoselectivity, to high yields of functionalized terpenic cyclopentanes with three contiguous stereogenic centers. These highly functionalized cyclopentanes are useful intermediates for the synthesis of several natural compounds that include this interesting subunit in their structure. Both the regioselectivity of the process leading to cyclopentanes and the stereoselectivity of the cyclization could be controlled by using malonyl derivatives or α,β-unsaturated nitriles as radical acceptors. The titanocene-mediated cyclization of suitably functionalized acyclic C10 epoxy-polyprenes proceeds with acceptable stereochemical control and excellent yields. The process takes place through 5-exo-trig ring closures and gives cyclopentanes with three contiguous stereogenic centers with peripheral functional groups that are suitable for constructing structurally complex natural products. Copyright
A strategy for position-selective epoxidation of polyprenols
Gnanadesikan, Vijay,Corey
supporting information; experimental part, p. 8089 - 8093 (2009/02/01)
An effective strategy has been developed for the efficient site-selective epoxidation of poylolefinic isoprenoid alcohols, based on the use of an internal control element for intramolecular reaction. The approach is illustrated by application to a series of polyisoprenoid alcohols (polyprenols) at substrate concentration of 0.5 mM. With polyprenol substrates having the hydroxyl function at one terminus, the internal epoxidation can be directed at the double bond of the polyprenol, which is either four or five away from the terminal hydroxyprenyl subunit.
Process for the preparation of unsaturated 4,5-allene ketones, 3,5-diene ketones and the corresponding saturated ketones
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, (2008/06/13)
Process for the preparation of unsaturated 4,5-allene ketones by reaction of tertiary propargyl alcohols with alkenyl alkyl ethers or ketals in the presence of aliphatic sulfonic acids or sulfonic acid salts.
