15356-60-2Relevant articles and documents
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Read,Grubb
, p. 188,193 (1931)
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Stereoselective reduction of menthone by molecularly imprinted polymers
Hedin-Dahlstroem, Jimmy,Shoravi, Siamak,Wikman, Susanne,Nicholls, Ian A.
, p. 2431 - 2436 (2004)
Polymeric chiral reductants selective for the reduction of (-)-menthone 1 to the diastereomeric products (-)-menthol 2 and (+)-neomenthol 3 were prepared by a covalentmolecular imprinting using 2 as the template. The LiAlH4 derivatized imprinted polymers altered the natural outcome of the reduction reaction (LiAlH4) from 2:1 [(-)-menthol:(+)-neomenthol] to 1:1. The reaction mechanism is discussed in terms of reaction site structure. The molecularly imprinted polymers demonstrated enantioselective recognition for 2 (0.15μmol enantioselective sites/g polymer) in batch binding experiments.
Apple-tree shoots and transformed carrot and apple roots used as biocatalysts in enantioselective acetate hydrolysis, alcohol oxidation and ketone reduction
Mironowicz, Agnieszka,Kromer, Krystyna
, p. 1655 - 1662 (1998)
(±)-1-Phenylethyl (1), (±)-1-(1-naphthyl)ethyl (2), (±)-1-(2-naphthyl)ethyl (3) and (±)-menthyl (4) acetates were hydrolyzed using apple-tree shoots and hairy roots of carrot and apple-tree to afford alcohols, which, subsequntly, in the same environment, were oxygenated to ketones. Pure (S)-1-(2-naphthyl)ethanol ((S)-(-)-7), (R)-1-phenylethyl acetate ((R)-(+)-1), (R)-1-(1-naphthyl)ethyl acetate ((R)-(+)-2). (S)-1-phenylethanol ((S)-(-)-5) and (-)-menthol (1R,25,5R)-(-)-8) have been produced.
Continuous synthesis of menthol from citronellal and citral over Ni-beta-zeolite-sepiolite composite catalyst
Er?nen, Kari,M?ki-Arvela, P?ivi,Martinez-Klimov, Mark,Muller, Joseph,Murzin, Dmitry Yu.,Peurla, Markus,Simakova, Irina,Vajglova, Zuzana
, (2022/04/03)
One-pot continuous synthesis of menthols both from citronellal and citral was investigated over 5 wt% Ni supported on H-Beta-38-sepiolite composite catalyst at 60–70 °C under 10–29 bar hydrogen pressure. A relatively high menthols yield of 53% and 49% and stereoselectivity to menthol of 71–76% and 72–74% were obtained from citronellal and citral respectively at the contact time 4.2 min, 70 °C and 20 bar. Citral conversion noticeably decreased with time-on-stream under 10 and 15 bar of hydrogen pressure accompanied by accumulation of citronellal, the primary hydrogenation product of citral, practically not affecting selectivity to menthol. A substantial amount of defuctionalization products observed during citral conversion, especially at the beginning of the reaction (ca. 1 h), indicated that all intermediates could contribute to formation of menthanes. Ni/H-Beta-38-sepiolite composite material prepared by extrusion was characterized by TEM, SEM, XPS, XRD, ICP-OES, N2 physisorption and FTIR techniques to perceive the interrelation between the physico-chemical and catalytic properties.
Heterogeneous Hydroxyl-Directed Hydrogenation: Control of Diastereoselectivity through Bimetallic Surface Composition
Shumski, Alexander J.,Swann, William A.,Escorcia, Nicole J.,Li, Christina W.
, p. 6128 - 6134 (2021/05/29)
Directed hydrogenation, in which product selectivity is dictated by the binding of an ancillary directing group on the substrate to the catalyst, is typically catalyzed by homogeneous Rh and Ir complexes. No heterogeneous catalyst has been able to achieve equivalently high directivity due to a lack of control over substrate binding orientation at the catalyst surface. In this work, we demonstrate that Pd-Cu bimetallic nanoparticles with both Pd and Cu atoms distributed across the surface are capable of high conversion and diastereoselectivity in the hydroxyl-directed hydrogenation reaction of terpinen-4-ol. We postulate that the OH directing group adsorbs to the more oxophilic Cu atom while the olefin and hydrogen bind to adjacent Pd atoms, thus enabling selective delivery of hydrogen to the olefin from the same face as the directing group with a 16:1 diastereomeric ratio.
