- Synthesis of Terpineol from Alpha-Pinene Catalyzed by α-Hydroxy Acids
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We report the use of five alpha-hydroxy acids (citric, tartaric, mandelic, lactic and glycolic acids) as catalysts in the synthesis of terpineol from alpha-pinene. The study found that the hydration rate of pinene was slow when only catalyzed by alpha-hydroxyl acids. Ternary composite catalysts, composed of AHAs, phosphoric acid, and acetic acid, had a good catalytic performance. The reaction step was hydrolysis of the intermediate terpinyl acetate, which yielded terpineol. The optimal reaction conditions were as follows: alpha-pinene, acetic acid, water, citric acid, and phosphoric acid, at a mass ratio of 1:2.5:1:(0.1–0.05):0.05, a reaction temperature of 70? C, and a reaction time of 12–15 h. The conversion of alpha-pinene was 96%, the content of alpha-terpineol was 46.9%, and the selectivity of alpha-terpineol was 48.1%. In addition, the catalytic performance of monolayer graphene oxide and its composite catalyst with citric acid was studied, with acetic acid used as an additive.
- Hu, Yi-Ming,Huang, Xiao-Rui,Meng, Zhong-Lei,Qin, Rong-Xiu,Wen, Ru-Si,Zhou, Yong-Hong
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- PROCESS FOR PREPARING A MIXTURE OF TERPENE ALCOHOLS
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The present invention relates to a process for preparing a mixture of terpene alcohols comprising limonene-4-ol and terpinene-4-ol from terpinolene epoxide via an isomerization and/or hydrogenation reaction in the presence of a copper catalyst.
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Page/Page column 13
(2017/09/15)
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- PROCESS FOR PREPARING TERPINENE-4-OL
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The present invention relates to a process for preparing terpinene-4-ol from limonene-4-ol via a hydrogenation reaction in the presence of a nickel catalyst.
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Page/Page column 9; 10; 11
(2017/09/09)
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- Biotransformations of terpenes by fungi from amazonian Citrus plants
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The biotransformations of (RS)-linalool (1), (S)-citronellal (2), and sabinene (3) with fungi isolated from the epicarp of fruits of Citrus genus of the Amazonian forest (i.e., C. limon, C. aurantifolia, C. aurantium, and C. paradisiaca) are reported. The
- Moreno Rueda, Maria Gabriela,Guerrini, Alessandra,Giovannini, Pier Paolo,Medici, Alessandro,Grandini, Alessandro,Sacchetti, Gianni,Pedrini, Paola
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p. 1909 - 1919
(2013/11/06)
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- Cloning and characterization of Pfl-1841, a 2-methylenebornane synthase in Pseudomonas fluorescens PfO-1
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The pfl-1841 gene from Pseudomonas fluorescens PfO-1 is the only gene in any of the three sequenced genomes of the Gram-negative bacterium P. fluorescens, that is, annotated as a putative terpene synthase. The predicted Pfl-1841 protein, which harbors the two strictly conserved divalent metal binding domains found in all terpene cyclases, is closely related to several known or presumed 2-methylisoborneol synthases, with the closest match being to the MOL protein of Micromonaspora olivasterospora KY11048 that has been implicated as a 2-methylenebornane synthase. A synthetic gene encoding P. fluorescens Pfl-1841 and optimized for expression in Escherichia coli was expressed and purified as an N-terminal His6-tagged protein. Incubation of recombinant Pfl-1841 with 2-methylgeranyl diphosphate produced 2-methylenebornane as the major product accompanied by 1-methylcamphene as well as other minor, monomethyl-homomonoterpene hydrocarbons and alcohols. The steady-state kinetic parameters for the Pfl-1841-catalyzed reaction were K M=110±13 nM and kcat=2.4±0.1×10 -2 s-1. Attempts to identify the P. fluorescens SAM-dependent 2-methylgeranyl diphosphate synthase have so far been unsuccessful.
- Chou, Wayne K.W.,Ikeda, Haruo,Cane, David E.
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supporting information; experimental part
p. 6627 - 6632
(2011/10/04)
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- A facile method for the rapid and selective deprotection of methoxymethyl (MOM) ethers
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We describe a rapid and efficient method for selective deprotection of methoxymethyl (MOM) ethers using ZnBr2 and n-PrSH, which completely removed MOM from diverse MOM ethers of primary, secondary, and tertiary alcohols or phenol derivatives. The deprotection takes less than ten minutes with both high yield and selectivity in the presence of other protecting groups. In addition, the rapid deprotection of MOM ethers of tertiary hydroxyls in high yield with no epimerization allows MOM to be a suitable protecting group for tertiary alcohols.
- Han, Jae Hyun,Kwon, Young Eun,Sohn, Jeong-Hun,Ryu, Do Hyun
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experimental part
p. 1673 - 1677
(2010/04/04)
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- Lithium-potassium superbases as key reagents for the base-catalysed isomerisation of some terpenoids
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Some representative monoterpenes have been isomerised under the influence of Schlosser's lithium-potassium mixed superbases, promoting β-elimination reactions. The results are compared with those obtained with butyllithium and LDA. Different selectivities and different reaction yields are achieved as a function of the base employed. These results confirm the particular reactivity of bimetallic reagents. In this paper it is proposed that the observed selectivities might depend on the conformational features of the substrate, on the strength of the organometallic reagent, as well as on steric requirements of the elimination reaction.
- Deagostino,Tivola,Prandi,Venturello
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p. 2856 - 2860
(2007/10/03)
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- Base-catalysed rearrangement of p-menth-1-en-4(8)-oxide
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p-Menth-1-en-4(8)-oxide (1), a tetrasubstituted spiro epoxide is normally resistant towards bases but under forcing condition with AIP rearranges to p-mentha-1,8-dien-4-ol (2).On the other hand, with t-BuOK, p-mentha-1,3-dien-8-ol (3) and p-mentha-1,4-dien-8-ol (4) are formed as the major products.These compounds readily get oxidised to p-cymen-8-ol (5), as seen in the reaction of 1 with N-LiEDA.
- Roy, Animesh,Gurudutt, K. N.,Rao, Sanjay
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p. 636 - 638
(2007/10/03)
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- Preparation of terpinen-4-ols and intermediates
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A method of preparing terpinen-4-ols and intermediates thereof, by reacting 1,4-cineole with an alkali metal aryl compound, resulting in an E2 elimination reaction of 1,4-cineole.
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- REDUCTIVE COUPLING OF ALLYLIC ACETATES WITH CARBONYL COMPOUNDS BY USING Pd(O)-SmI2 SYSTEM
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Reductive coupling of allylic acetates with carbonyl compounds proceeded by SmI2 in the presence of catalytic Pd(O) to yield homoallylic alcohols.
- Tabuchi, Takanori,Inanaga, Junji,Yamaguchi, Masaru
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p. 1195 - 1196
(2007/10/02)
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- REACTIONS OF OXIRANES WITH ALKALI METALS: INTERMEDIACY OF RADICAL-ANIONS
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Reaction of oxiranes with alkali metals in aprotic solvents yields a variety of products depending on the nature of the metal and the structure of the oxirane.Deoxygenation to olefins is the major reaction in case of lithium.Rearrangement to carbonyl compounds, reduction to alcohols and formation of dimeric products occur when oxiranes are treated with sodium.All the reactions could be rationalised by a mechanism involving an initial single electron transfer leading to the formation of radical-anion intermediate.
- Gurudutt, K. N.,Pasha, M. A.,Ravindranath, B.,Srinivas, P.
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p. 1629 - 1632
(2007/10/02)
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