- Liquid phase acetoxylation of α-pinene over Amberlyst-70 ion-exchange resin
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Heterogeneously-catalyzed and solvent-catalyzed liquid phase acetoxylation of α-pinene with acetic acid acting as both a solvent and a reagent was studied. Both solvent-catalyzed and catalytic experiments were carried out and various reaction conditions were studied. The influence of temperature, pressure, solvent and gas milieu were taken into account. Bornyl, fenchyl, verbenyl as well as α-terpinyl acetates, limonene, camphene and γ-terpinene were found among reaction products. The addition of the catalyst allowed for maximization of the yield of bornyl acetate. The predominant products obtained were α-terpinyl, verbenyl and bornyl acetates. The reaction pathways were identified and evaluated. The aim of this work was to study the feasibility of batch acetoxylation of α-pinene. The analysis of the complex product distribution is not trivial and, consequently, resolving the reaction network was important. The optimized reaction conditions were searched for aiming at an efficient conversion of α-pinene to a mixture of valuable products.
- Golets,Ajaikumar,Blomberg,Grundberg,W?rn?,Salmi,Mikkola
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scheme or table
p. 43 - 50
(2012/10/18)
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- INVESTIGATION OF THE SYNTHESIS OF VERBENYL COMPOUNDS EFFECTIVE ATTRACTANTS OF COCKROACH SPECIES, BY ACYLOXYLATION OF α-PINENE
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The synthesis of verbenyl acetate (Ia) and propionate (Ib) was inestigated by acyloxylation of α-pinene with lead(IV) acetate (LTA), lead(IV) propionate (LTP), mercury(II) acetate (MA) and iodosobenzene diacetate (IBDA) in neutral and acidic medium.The neutral medium is better for the formation of Ia and Ib, because the acidic medium helps the opening of cyclobutane ring of α-pinene.These methods can be used for large scale preparation of insect attractants to cockroach species (Blatella germanica, Blatella orientalis and Periplaneta americana).
- Vinczer, Peter,Kajtar-Peredy, Maria,Juvancz, Zoltan,Novak, Lajos,Szantay, Csaba
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p. 1719 - 1730
(2007/10/02)
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- Microbial Allyl Rearrangement and Resolution of Acetates of Unsaturated Cyclic Terpene Alcohols by Pseudomonas sp. NOF-5 Strain
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Microbial hydrolysis of the acetates of unsaturated cyclic terpene alcohols by Pseudomonas sp.NOF-5 isolated from soil was investigated. (+/-)-trans-Carveyl acetate ((+/-)-trans-3) was enantioselectively hydrolyzed with NOF-5 strain to give (-)-trans-carveol ((-)-trans-2 of 86.6percent optical purity).However, the hydrolysis of (+/-)-cis-3 was less enantioselective, while (+/-)-piperitylacetate ((+/-)-6, a cis and trans mixture) was hydrolyzed to give the (-)-trans- and (-)-cis-piperitols ((-)-trans-5 and (-)-cis-5) in a poor optical yield.In this case, other tert-alcohols, (+)-trans- and (-)-cis-2-p-menthen-1-ols ((+/-)-trans-7 and (-)-cis-7, were also produced.Furthermore, microbial and enzymic allyl rearrangements of (+)-trans-6 and (-)-trans-verbenylacetate ((-)-trans-11) were studied.Biological treatment of (+)-trans-6 and (-)-trans-11 with NOF-5 or its esterase gave (+)-trans- and (-)-cis-7 and (+)-cis-3-pinen-2-ol ((+)-cis-12), respectively.
- Inagaki, Takashi,Ueda, Hiroo
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p. 2635 - 2640
(2007/10/02)
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- METAL-CATALYZED REARRANGEMENTS OF ALLYLIC ESTERS
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It has been shown that Pd(CH3CN)2Cl2 catalyzes the rearrangement of allylic esters.Carbamates rearrange more rapidly than acetates which in turn rearrange more rapidly than carbonates.Allylic carbamates are more rapidly isomerized by Pd(CH3CN)2Cl2 than by Hg(OCOCF3)2.The rearrangement proceeds well except in cases where the central carbon of the allylic system is fully substituted.In contrast to the reported rearrangement of allylic carbamates by Hg2+ and previous reports of Pd2+-catalyzed rearrangements of allylic esters, this work showed the latter are extremely E specific; thus E allylic acetates yield equilibrium mixtures free of Z allylic isomers, under conditions in which Z allylic acetates are unreactive.This E specificity is applied to stereospecific 1,3-diene synthesis from bis E,Z-allylic acetates
- Oehlschlager, A. C.,Mishra, P.,Dhami, S.
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p. 791 - 797
(2007/10/02)
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