- One-pot synthesis of 2-alkyl cycloketones on bifunctional Pd/ZrO2 catalyst
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2-Alkyl cycloketones are essential chemicals and intermediates for synthetic perfumes and pesticides, which are conventionally produced by multistep process including aldol condensation, separation and hydrogenation. In present work, a batch one-pot cascade approach using aldehydes and cycloketones as the raw materials, and a bifunctional Pd/ZrO2 catalyst was developed for the synthesis of 2-alkyl cycloketones, e.g., cyclohexanone and cycloheptanone. Very high aldehydes (except for paraldehyde with large steric hindrance) conversion and high yields for 2-alkyl cycloketones (e.g., 99 % of conversion for n-butanal and 76 wt.% of yield for 2-butyl cyclohexanone) were obtained at mild temperature of 140 °C. After 10 cycles of reuse, Pd/ZrO2 catalyst showed slight deactivation (ca. 5 % conversion and 10 % yield losses), due to the coke on the catalyst. However, the performance of the catalyst was completely recovered after an oxidative regeneration.
- Xue, Weiyang,Gu, Bin,Wu, Huiling,Liu, Mengyang,He, Songbo,Li, Jingmei,Rong, Xin,Sun, Chenglin
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- Catalytic oxidation of alkyl- and cycloalkylcyclanones into lactones
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Pilot-plant syntheses of alkyl and cycloalkylcyclanones and their subsequent liquid-phase oxidation into lactones are described. Characteristics of resulting intermediates and target products are reported.
- Abbasov,Alimardanov,Suleimanova
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p. 621 - 626
(2007/10/03)
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- New Method for Generation of β-Oxido Carbenoid via Ligand Exchange Reaction of Sulfoxides: A Versatile Procedure for One-Carbon Homologation of Carbonyl Compounds
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A new procedure for one-carbon homologation of carbonyl compounds is described.The method is based on the rearrangement of β-oxido carbenoid which is generated via the ligand exchange reaction of the sulfinyl group of α-chloro β-hydroxy sulfoxide with tert-butyllithium.Addition of the carbanion of aryl 1-chloroalkyl sulfoxides to carbonyl compounds gave the adducts in good yields.The β-oxido carbenoid rearrangement of the adducts gave one-carbon homologated carbonyl compounds having an α-alkyl substituent.A similar reaction of the adducts derived from carbonyl compounds with chloromethyl p-tolyl sulfoxide yielded a procedure for a methylene insertion.The stereochemistry of the β-oxido carbenoid rearrangenment is also discussed.
- Satoh, Tsuyoshi,Itoh, Norifumi,Gengyo, Kaoru,Takada, Sae,Asakawa, Naoyuki,et al.
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p. 11839 - 11852
(2007/10/02)
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- Resolution of Racemic ε-Lactones
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Kinetic resolution of racemic ε-lactones by Pig Liver Esterase give optically active R (+) ε-lactones.When alkyl group is higher than propyl, Horse Liver Esterase leads to the destruction of the opposite enantiomer.Enantiomeric excess is easily evaluated by G.C. on a chiral stationary phase.
- Fellous, R.,Lizzani-Cuvelier, L.,Loiseau, M. A.,Sassy, E.
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p. 343 - 346
(2007/10/02)
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- A novel method for generation of carbenoid from α-chloro sulfoxides: A new and versatile procedure for one-carbon homologation of carbonyl compounds to carbonyl compounds having an α-alkyl substituent
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Addition of the carbanion of 1-chloroalkyl p-tolyl sulfoxides to carbonyl compound gave the adducts, which were treated with a base followed by t-butyllithium to afford one-carbon homologated carbonyl compounds having an alkyl group at the α-position, via the β-oxido carbenoids, in moderate to good yields.
- Satoh, Tsuyoshi,Itoh, Norifumi,Gengyo, Kaoru,Yamakawa, Koji
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p. 7543 - 7546
(2007/10/02)
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- Removal of α-Hydroxy Group of Acyloins and Their Derivatives with Vanadium(II)-THF Complex
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α-Hydroxy ketones (acyloins) and their acetate or mesylate derivatives were reduced to the corresponding ketones in good yields by treatment with 2 complex prepared in situ from VCl3(THF)3 and zinc.
- Inokuchi, Tsutomu,Kawafuchi, Hiroyuki,Torii, Sigeru
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p. 1895 - 1896
(2007/10/02)
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- ENZYMATIC RESOLUTION OF RACEMIC LACTONES
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PPL, HLE or PLE enzymatic resolution of racemic γ, δ and ε-lactones gives optically active lactones (ee: 60 to 90percent).
- Blanco, L.,Guibe-Jampel, E.,Rousseau, G.
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p. 1915 - 1918
(2007/10/02)
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- Hydroboration. 67. Cyclic Hydroboration of Acyclic α,ω-Dienes with 9-Borabicyclononane/Borane-Dimethyl Sulfide
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Hydroboration of acyclic α,ω-dienes, 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,11-dodecadiene, and 1,13-tetradecadiene, with 2 molar equiv of 9-borabicyclononane (9-BBN), followed by redistribution of the resulting dumbbell-shaped trialkylboranes with 1 molar equiv of borane-methyl Sulfide complex (BMS), has been investigated.With 1,3-butadiene, the initial redistribution product, the five-membered boracyclane, borolane, underwent a rapid ring-opening reaction to give the known 1,6-diboracyclodecane. 1,4-Pentadiene and 1,5-hexadiene afforded the corresponding boracyclanes, borinane and borepane, in quantitative yields.With all other dienes, the initial redistribution products were polymeric.They were converted to the methyl esters by treatment with methanol, and these products were depolymerized into cyclic derivatives in 88-98percent yield by vacuum distillation at 175-200 deg C.In every case the cyclization was accompanied by varying amounts of isomerization so that the major products were both the parent B-methoxyboracyclane and the corresponding B-methoxy-2-n-alkylborinane.Thus, 1,6-heptadiene afforded B-methoxyborocane and B-methoxy-2-ethylborinane in 3:1 ratio and a total yield of 95percent.With 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene and 1,11-dodecadiene, the isomerized product constituted the major constituent of the distillate. 1,13-Tetradecadiene afforded the parent boracyclane and the isomer in a 47:53 ratio and a combined yield of 82percent.The B-methoxyboracyclanes were converted to the corresponding cyclic ketones by the DCME reaction in 55-65percent yield.
- Brown, Herbert C.,Pai, Ganesh G.,Naik, Ramachandra G.
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p. 1072 - 1078
(2007/10/02)
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