7616-79-7Relevant academic research and scientific papers
Silica-catalysed and highly stereoselective convergent and nonconvergent rearrangements of menthone enol acetate epoxides: Easy access to the four α-hydroxymenthone stereoisomers
Tranchimand, Sylvain,Faure, Bruno,Naubron, Jean-Valere,Alphand, Veronique,Archelas, Alain,Iacazio, Gilles
experimental part, p. 4365 - 4372 (2012/09/07)
During a program dedicated to the biocatalytic access of structurally useful α-hydroxy ketones, we made the unexpected observation that epoxy enol acetates derived from (+)- and (-)-menthone stereoselectively rearranged on exposure to silica through a diastereoselective process, providing easy access to the complete set of α-hydroxymenthone stereoisomers. The absolute configurations of the four stereoisomers were unambiguously established by IR-VCD and X-ray diffraction, thus clarifying some literature discrepancy. Two of the four stereoisomers could also be obtained through astereoconvergent process, thus avoiding the inherent 50 % yield limitations of such diastereoselective reactions. A solvent-free version allowing an extremely rapid reaction ( 2 h) is also described. Finally, the observed diastereoselection was investigated by DFT calculations. Epoxy enol acetates derived from menthone unexpectedly rearranged diastereoselectively on exposure to silica, giving easy access to the complete set of α-hydroxymenthone stereoisomers. Two of the four stereoisomers were also available through a diastereoconvergent process. Finally, the observed stereoselection was investigated by DFT calculations. Copyright
Enantioselectivity in the Biotransformation of Mono- and Bicyclic Monoterpenoids with the Cultured Cells of Nicotiana tabacum
Hamada, Hiroki
, p. 869 - 878 (2007/10/02)
The biotransformation of the enantiomeric pairs of p-menthane and bicyclo and heptane derivatives with the cultured cells of Nicotiana tabacum was investigated.It was found that (i) the cultured cells discriminate the enantiomers of p-menthan-2-ol and bicycloheptan-2-ol and bicycloheptan-3-ol derivatives, and enantioselectively convert these alcohols to the corresponding ketones, (ii) the cells reduce the carbonyl group of p-methan-2-one derivatives to a high extent, but not that of p-menthan-3-ones, and (iii) the cells discriminate the enantiomers of bicyclohept-2-en-4-one (verbenone) and enantioselectively reduce the C-C double bond of the (1S,5S)-enantiomer.
BIOTRANSFORMATION OF 3-OXO-p-MENTHANE DERIVATIVES BY CULTURED CELLS OF NICOTIANA TABACUM
Suga, Takayuki,Hirata, Toshifumi,Hamada, Hiroki,Murakami, Satoru
, p. 1041 - 1044 (2007/10/02)
The biotransformation of (1R)-(+)-p-menth-4(8)-en-3-one and (1R,4S)-(-)- and (1R,4R)-(+)-p-menth-3-ones with a suspension of cultured cells of Nicotiana tabacum was investigated.It was found that (i) the cultured cells regio- and stereoselectively hydroxylated the 4-position of (1R,4S)- and (1R,4R)-p-menth-3-ones to give (1R,4R)- and (1R,4S)-4-hydroxy-p-menth-3-ones, respectively and (ii) the cultured cells stereoselectively reduced the C-C double bond of the p-menth-4(8)-en-3-one from the si-face at C-4 and then the carbonyl group from the re-face.Key Word Index: Nicotiana tabacum; Solanaceae; tissue culture; biotransformation; hydroxylation; reduction; stereoselectivity; 3-oxo-p-menthanes.
Stereoselectivity in Oxidative and Reductive Transformations of p-Menthane Derivatives with the Cultured Cells of Nicotiana tabacum
Suga, Takayuki,Hamada, Hiroki,Hirata, Toshifumi,Izumi, Shunsuke
, p. 903 - 906 (2007/10/02)
The biotransformation of the enantiomeric pairs of 2- and 3-oxygenated p-methane derivatives with the cultured cells of Nicotiana tabacum was investigated.It was found that (I) the cultured cells transform only 2-oxygenated p-menthane derivatives to a great extent, (ii) the cultured cells cause the highly stereospecific reduction for (1R,4R)-2-oxo-p-menthane, whereas this is not the case for its enantiomer, and (iii) the cultured cells enantioselectively oxidize the hydroxyl group of 2-hydroxyl-p-methanes.
