28664-18-8Relevant academic research and scientific papers
Two-step continuous flow synthesis of α-terpineol
Aguillon, Anderson R.,Le?o, Raquel A. C.,de Carvalho, Beatriz L. C.,de Souza, Rodrigo O. M. A.
, (2021)
α-Terpineol is a naturally occurring monoterpene present in essential oils, of high value on the market as it is widely used as flavoring in the cosmetics and food industry. This study aims to produce α-terpineol by two different synthetic strategies, using both batch and continuous flow systems, focusing on the optimization of the process, improving the reaction conversion and selectivity. The first strategy adopted was a one-stage hydration reaction of (+)-α-pinene by an aqueous solution of chloroacetic acid (molar ratio 1:1 between pinene and the acid) in continuous flow conditions. This reaction was carried out at 80 °C with a residence time of 15 min, obtaining good conversion (72%) and selectivity (76%), and productivity of 0.53 kg.day?1. The second strategy accomplished was a two-step cascade reaction with (+)-limonene as starting material, where the first step is a chemospecific double bond addition using trifluoroacetic acid, and the second step is the basic hydrolysis of the ester promoted by a solution of sodium hydroxide (2.25 M) in methanol (1:1). This reaction was adapted to a continuous flow condition, where all steps involved a residence time of 40 min, at 25 °C, with no quenching between steps required, with 97% conversion, 81% selectivity and up to 0.14 kg.day?1.
Chemospecific Preparation of Both Enantiomers of α-Terpinyl Trifluoroacetate
De Mattos, Marcio C. S.,Coelho, Ricardo B.,Sanseverino, Antonio M.
, p. 541 - 545 (2004)
(R)- and (S)-α-Terpinyl trifluoroacetate can easily be prepared in 56-64% yield and high ee by the reaction of (R)- and (S)-limonene with trifluoroacetic acid in cyclohexane. The products were fully characterized by 1H and 13C NMR, I
Reaction of 3-carene with perfluoroalkanoic acids
Trishin, Yu. G.,Fedorov
, p. 1743 - 1749 (2016)
The addition of perfluoroalkanoic acids to 3-carene involves opening of the cyclopropane ring at the peripheral bonds with formation of a mixture of isomeric p-menth-1-en-8-yl and m-menth-1-en-8-yl perfluoroalkanoates. The reaction rate decreases as the length of the perfluoroalkyl radical of the acid increases. Trichloroacetic acid reacted with 3-carene at a lower rate than does trifluoroacetic acid, but the products are analogous p-menth-1-en-8-yl and m-menth-1-en-8-yl trichloroacetates.
Total Synthesis of (-)-Aristoquinoline via an Intramolecular Nitrilium Ion Cyclization
Gujarati, Priyansh D.,Reber, Keith P.
, (2021/12/02)
The enantioselective total synthesis of the alkaloid aristoquinoline has been achieved in seven steps and 26% overall yield. A new preparation of the useful synthetic building block (-)-α -terpinyl amine was also developed in order to avoid stoichiometric mercury reagents or azide-containing intermediates. Key steps in the optimized synthetic route include an intramolecular nitrilium ion cyclization to form the characteristic azabicyclo[3.3.1]nonane ring system and a diastereoselective reduction of the resulting imine mixture to afford the natural product. An isomer of aristoquinoline containing an exocyclic alkene was also obtained and found to exhibit unusual chromatographic and spectroscopic properties.
Synthesis of Aristoquinoline Enantiomers and Their Evaluation at the α3β4 Nicotinic Acetylcholine Receptor
Argade, Malaika D.,Straub, Carolyn J.,Rusali, Lisa E.,Santarsiero, Bernard D.,Riley, Andrew P.
supporting information, p. 7693 - 7697 (2021/08/16)
The first synthesis of aristoquinoline (1), a naturally occurring nicotinic acetylcholine receptor (nAChR) antagonist, was accomplished using two different approaches. Comparison of the synthetic material's spectroscopic data to that of the isolated alkaloid identified a previously misassigned stereogenic center. An evaluation of each enantiomer's activity at the α3β4 nAChR revealed that (+)-1 is significantly more potent than (-)-1. This unexpected finding suggests that naturally occurring 1 possesses the opposite absolute configuration from indole-containing Aristotelia alkaloids.
Traceless Silylation of β-C(sp3)-H Bonds of Alcohols via Perfluorinated Acetals
Bunescu, Ala,Butcher, Trevor W.,Hartwig, John F.
supporting information, p. 1502 - 1507 (2018/02/09)
We report the silylation of primary C-H bonds located β to secondary and tertiary alcohols by exploiting perfluorinated esters as traceless directing groups. The conversion of a secondary or tertiary alcohol to a perfluoroalkyl ester and conversion of the ester to the corresponding silyl acetals by hydrosilylation allows for selective β-C(sp3)-H silylation catalyzed by the combination of [Ir(cod)OMe]2 and Me4Phen (3,4,7,8-tetramethyl-1,10-phenanthroline) to form 6-membered dioxasilinane. Tamao-Fleming oxidation of these dioxasilinane leads to 1,2 diols. The developed sequence was applied to a series of natural products containing hydroxyl groups.
Stolonidiol: Synthesis, Target Identification, and Mechanism for Choline Acetyltransferase Activation
Mason, Jeremy W.,Schmid, Cullen L.,Bohn, Laura M.,Roush, William R.
supporting information, p. 5865 - 5869 (2017/05/04)
Stolonidiol, a marine natural product, has been reported to potentiate the activity of choline acetyltransferase (ChAT), the enzyme that produces the neurotransmitter acetylcholine. Here we report the total synthesis of stolonidiol starting from (R)-(+)-limonene. To identify the mechanism by which ChAT activity is increased, we sought to identify the biological target of stolonidiol. We show that stolonidiol binds to the phorbol ester binding site of protein kinase C (PKC), induces translocation of PKC to the cell membrane, and activates kinase activity. Furthermore, we confirmed the increase in ChAT activity observed upon treatment of cells with stolonidiol and show that this effect is mediated by PKC. Collectively, our data strongly suggest that PKC activation by stolonidiol is responsible for the resulting potentiation of ChAT activity.
Addition of perfluoroalkanoic acids to (R)-(+)-limonene
Trishin,Shafeeva,Tamm
, p. 545 - 550 (2013/06/27)
Perfluoroalkanoic acids with different lengths of the perfluoroalkyl radical selectively add under mild conditions to the exocyclic double C=C of limonene to give the corresponding Markovnikov adducts, α-terpinyl perfluoroalkanoates. The reaction in the p
A practical synthesis of d-α-terpineol via Markovnikov addition of d-limonene using trifluoroacetic acid
Yuasa, Yoshifumi,Yuasa, Yoko
, p. 1231 - 1232 (2012/12/23)
d-α-Terpineol (1), which is a useful flavor and fragrance compound, has been synthesized from d-limonene by Markovnikov addition using trifluoroacetic acid, followed by hydrolysis in 76% yield with 98% purity.
CYCLIZATION OF SOME LINEAR TERPENOLS INITIATED BY "ACTIVATED" DMSO
Surkova, A. A.,Lozanova, A. V.,Dragan, V. A.,Gur'yan, V. A.,Moiseenkov, A. M.
, p. 760 - 762 (2007/10/02)
It was shown that the acylhydroxysulfonium salt generated in situ from DMSO and trifluoroacetic anhydride causes low-temperature cyclization of geraniol, linalool, and nerol in an aprotic medium to a mixture of p-menthane monoterpenoids, and the maximum yield is obtained in the case of the last two terpenols.A similar result was obtained for E-nerolidol.
