Abstract In newly initiated cellsuspension cultures of Nicotianatabacum , (4 R )-(−) and (4 S )(+)-carvoximes and (1 S ,4 R )(+)-dihydrocarvoxime were hydrolysed to the corresponding ketones and then the resultant ketones were reduced to the corresponding alcohols.
摘要 在烟草新开始的细胞悬浮培养中,(4 R )-(-) 和(4 S )(+)-香芹酮肟和(1 S ,4 R )(+)-二氢香芹酮肟被水解成相应的酮,然后生成的酮被还原为相应的醇。
Selective one-pot carvone oxime hydrogenation over titania supported gold catalyst as a novel approach for dihydrocarvone synthesis
作者:Yu. S. Demidova、E.V. Suslov、O.A. Simakova、K.P. Volcho、N.F. Salakhutdinov、I.L. Simakova、D. Yu. Murzin
DOI:10.1016/j.molcata.2016.04.013
日期:2016.8
for the first time that dihydrocarvone can be selectively produced by gold-catalyzed one-pot transformation of carvone oxime. This reaction was carried out at 100 °C under hydrogen pressure of 9 bar over 1.9 wt.% Au/TiO2 catalyst using methanol as a solvent. Dihydrocarvone synthesis was shown to occur via carvone formation with the subsequent hydrogenation of its conjugated CC double bond. Application
摘要 首次表明金催化香芹酮肟一锅转化可选择性制备二氢香芹酮。该反应在 100 °C 和 9 bar 的氢气压力下在 1.9 wt.% Au/TiO2 催化剂上使用甲醇作为溶剂进行。二氢香芹酮的合成显示通过香芹酮的形成以及随后其共轭的CC双键的氢化而发生。首次报道了Au/TiO2催化剂在烯烃CC官能团的脱肟和选择性加氢中的应用。这些步骤的组合优化了从香芹酮肟生产二氢香芹酮的合成方法,香芹酮肟是从柠檬烯合成香芹酮的关键中间体。尽管反应速率比香芹酮低,在香芹酮肟氢化的情况下,观察到对反式二氢香芹酮的立体选择性显着增加。反式和顺式二氢香芹酮的比例接近 4.0,而香芹酮加氢的比例为 1.8。
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作者:V. D. Kolesnik
DOI:10.1023/a:1023902621846
日期:——
The reaction of dibenzylphosphine oxide with O-methyloximes of some alpha,beta-unsaturated ketones results in the phosphorylation at the P-carbon atom to form methoxyiminophosphine oxides, whereas the reaction of dibenzylphosphine oxide with O-methyloximes of alpha,beta-unsaturated aldehydes affords aminodihydrophosphole oxides.
Synthesis of New 1-Adamantanecarboxylic Acid Derivatives
作者:E. A. Dikusar1'、N. G. Kozlov、V. I. Potkin、A. P. Yuvchenko、N. V. Kovganko
DOI:10.1023/b:rujo.0000034968.28257.e9
日期:2004.3
Reactions of 1-adamantanecarbonyl chloride with functionally substituted alcohols, phenols, amines, thiols, and ketone oximes gave hitherto unknown 1-adamantanecarboxylic acid esters, amides, and thio esters, including those containing a peroxide group.
Regiospecificity and isotope effects associated with the methyl-methylene eliminations in the enzyme-catalyzed biosynthesis of (R)- and (S)-limonene
作者:Hyung Jung Pyun、Robert M. Coates、Kurt C. Wagschal、Paul McGeady、Rodney B. Croteau
DOI:10.1021/jo00067a037
日期:1993.7
[8-H-3]-, [8,8,9,9-H-2(4)]-, and [1-H-3,8,9-H-2(6)] geranyl diphosphates (1-t, 1-d4, and 1-d6,t) were synthesized and used as substrates for several monoterpene cyclases to determine the regiospecificity and isotope effects attending the terminating proton transfers in the enzyme-catalyzed biosynthesis of (R)- and (S)-limonene. Degradation of enantiomeric [H-3]limonenes produced by cyclization Of 1-t with the (+)- and (-)-pinene cyclases (synthases) from Salvia officinalis demonstrated that the eliminations occur at both the cis- (55-65%) and trans-methyl (45-35%) groups. In contrast, the terminating eliminations in the formation of (+)- and (-)-limonene catalyzed by limonene cyclasses from Citrus sinensis and Perilla frutescens, respectively, were shown by degradation to occur exclusively (greater-than-or-equal-to 97-98%) at the cis terminal methyl group. The intramolecular isotope effects for the methyl-methylene elimination in limonene biosynthesis catalyzed by (+)- and (-)-pinene cyclases from S. officinalis were found to be k(H)/k(D) = 2.3 +/- 0.2 and 5.9 +/- 0.5, respectively, by GC/MS determinations of [H-2]-limonene derived from enzymatic cyclizations of 1-d4. Similar experiments with (-)-limonene cyclase from Mentha spicata resulted in k(H)/k(D) = 4.0 +/- 0.4. Incubations of 1-d6,t with pinene and bornyl PP cyclases from S. officinalis exhibited significant remote isotope effects (k(H)/k(D) = 1.16-1.27) on the total rate of monoterpene formation which suggest that the initial cyclization step of the enzyme-bound linalyl diphosphate intermediate is an important component of the overall rate of the enzymatic reactions. The isotope effects on the partitioning of the alpha-terpinyl carbocation intermediate between bicyclization and elimination to limonene were determined from the effects of deuterium substitution on the product ratios derived from enzymatic cyclization of 1-d6,t. The small size of these product isotope effects (k(H)/k(D)) = 1.2-1.7) is attributed to a conformational inversion of the alpha-terpinyl ion to a half-chair conformer prior to proton elimination to limonene, thereby rendering the bicyclizations relatively immune to the intrinsic deuterium isotope effect. The regiospecific proton transfers from the cis terminal methyl group effected by the limonene cyclases from Citrus and Perilla are attributed to the minimization of charge separation in the transition state.