3796-70-1Relevant articles and documents
Corey,E.J.,Kuwajima,I.
, p. 487 - 489 (1972)
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 %.
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.
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.
