8022-83-1Relevant academic research and scientific papers
Matteson Reaction under Flow Conditions: Iterative Homologations of Terpenes
Kuhwald, Conrad,Kirschning, Andreas
supporting information, p. 4300 - 4304 (2021/05/26)
The Matteson reaction is ideally suited for flow chemistry since it allows iterative homologation of boronate esters. The present study provides accurate data on reaction times of the individual steps of the Matteson reaction, which occurs in less than 10 s in total. The protocol allows terpenes to be (per-)homologated in a controlled manner to yield homo-, bishomo-, and trishomo-terpenols after oxidative workup. The new terpene alcohols are validated with respect to their olfactoric properties.
Iridoid Sex Pheromone Biosynthesis in Aphids Mimics Iridoid-Producing Plants
Partridge, Suzanne J.,Withall, David M.,Caulfield, John C.,Pickett, John A.,Stockman, Robert A.,Oldham, Neil J.,Birkett, Michael A.
supporting information, p. 7231 - 7234 (2021/04/21)
Biosynthesis of (1R,4aS,7S,7aR)-nepetalactol (1) and (4aS,7S,7aR)-nepetalactone (2) in plants involves iridoid synthase (ISY), an atypical reductive cyclase that catalyses the reduction of 8-oxogeranial into the reactive enol of (S)-8-oxocitronellal, and cyclization of this enol intermediate, either non-enzymatically or by a nepetalactol-related short chain dehydrogenase enzyme (NEPS) that yields the nepetalactols. In this study, we investigated the biosynthesis in vivo of 1 and 2 in the pea aphid, Acyrthosiphon pisum, using a library of isotopically-labelled monoterpenoids as molecular probes. Topical application of deuterium-labelled probes synthesized from geraniol and nerol resulted in production of 2H4?lactol 1 and 2H4?lactone 2. However, deuterium incorporation was not evident using labelled probes synthesized from (S)-citronellol. These results suggest that iridoid biosynthesis in animals, specifically aphids, may follow a broadly similar route to that characterised for plants.
Molybdenum-modified mesoporous SiO2as an efficient Lewis acid catalyst for the acetylation of alcohols
Hlatshwayo, Xolani S.,Ndolomingo, Matumuene Joe,Bingwa, Ndzondelelo,Meijboom, Reinout
, p. 16468 - 16477 (2021/05/19)
A suitable, expeditious and well-organized approach for the acetylation of alcohols with acetic anhydride in the presence of 5%MoO3-SiO2 as an optimum environmentally benign heterogeneous catalyst was developed. The high surface area obtained for 5%MoO3-SiO2, 101 m2 g-1 compared to other catalysts, 22, 23, and 44 m2 g-1 for 5%WO3-ZrO2, 5%WO3-SiO2, and 5%MoO3-ZrO2, respectively, appears to be the driving force for better catalytic activity. Amongst the two dopants used, molybdenum oxide is the better dopant compared to its tungsten oxide counterpart. High yields of up to 86% were obtained with MoO3 doping while WO3 containing catalysts did not show any activity. Other reaction parameters such as reactor stirring speed, and solvent variation were studied and revealed that the optimum stirring speed is 400 rpm and cyclohexane is the best solvent. Thus, the utilization of affordable and nontoxic materials, short reaction times, reusability, and producibility of excellent yields of the desired products are the advantages of this procedure.
Ring-Closing Metathesis of Aliphatic Ethers and Esterification of Terpene Alcohols Catalyzed by Functionalized Biochar
Kerton, Francesca M.,MacQuarrie, Stephanie L.,Vidal, Juliana L.,Wyper, Olivia M.
supporting information, p. 6052 - 6056 (2021/12/10)
Functionalized biochars, renewable carbon materials prepared from waste biomass, can catalyze transformations of a range of oxygen-containing substrates via hydrogen-bonding interactions. Good conversions (up to 75.2 %) to different O-heterocycles are obtained from ring-closing C?O/C?O metathesis reactions of different aliphatic ethers under optimized conditions using this heterogeneous, metal-free, and easy separable catalyst. The diversity in the sorts of O-containing feedstocks is further demonstrated by the utilization of functionalized biochar to promote the esterification of terpene alcohols, an important reaction in food and flavor industries. Under the optimized conditions, full conversions to various terpene esters are obtained. Moreover, both of the reactions studied herein are performed under neat conditions, thus increasing the overall sustainability of the process described.
Method for synthesizing acetate perfume
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Paragraph 0051-0053; 0074-0076, (2021/01/15)
The invention provides a method for synthesizing acetate by alcohol esterification, which comprises the following steps: by using enol acetate as an esterification reagent, esterifying a primary alcohol, secondary alcohol or tertiary alcohol substrate at high selectivity and high yield under the action of an acidic catalyst to obtain the corresponding acetate products. The method has the main advantages that the synthesis method is novel, enol acetate is used as an esterification reagent, reaction byproducts are micromolecular acetaldehyde or acetone and the like, and the micromolecular compounds do not show acidity and are low in boiling point, so that rearrangement side reaction of an alcohol substrate cannot be caused; and the small molecule byproduct can be conveniently removed from the reaction solution, so that the esterification reaction is promoted to be completely carried out, the reaction stability is good, and the yield is high.
Total Synthesis of Isohericenone J via a Stille Coupling Reaction
Cao, Wei,Chen, Ping,Tang, Yu
, p. 1701 - 1705 (2020/06/08)
The first total synthesis of isohericenone J is reported. Key features of this synthetic strategy are a Friedel-Crafts reaction to construct the isobenzofuranone unit and a Pd-catalyzed Stille coupling reaction for the formation of the C5-C1′ bond, generating the natural product, as well as one of its isomers, in 6.0% overall yield in eight steps. This strategy provides a foundation for the synthesis of challenging isobenzofuranone and isoindolinone-type derivatives.
Synthesis method of geranyl acetate
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Paragraph 0078-0103; 0108-0115, (2020/11/01)
The invention relates to the technical field of preparation of flavors and fragrances, in particular to a synthesis method of geranyl acetate. The synthesis method of geranyl acetate comprises the following steps of: mixing acetic acid, geraniol and a polymerization inhibitor, heating the mixture to 60-140 DEG C, then adding a catalyst, and starting stirring; detecting the content of acetic acid in the reaction solution every 20-60 minutes, and stopping the reaction when the content of acetic acid is stable. According to the synthesis method of geranyl acetate, cation exchange resin is used asa catalyst, the catalytic activity and selectivity are excellent, other side reactions are not found, the reaction liquid is basically colorless, and geranyl acetate obtained through purification islighter in color and luster than geranyl acetate obtained through catalysis of concentrated sulfuric acid. Meanwhile, the catalytic system provided by the invention has the advantages of easiness in separation from a product, small corrosion to equipment, no environmental pollution, reusability and the like.
Allylic Amination of Alkenes with Iminothianthrenes to Afford Alkyl Allylamines
Chen, Junting,Cheng, Qiang,Lin, Songyun,Ritter, Tobias
supporting information, p. 17287 - 17293 (2020/11/02)
Allylic C-H amination is currently accomplished with (sulfon)amides or carbamates. Here we show the first allylic amination that can directly afford alkyl allylamines, enabled by the reactivity of thianthrene-based nitrogen sources that can be prepared from primary amines in a single step.
Synergistic factors ensue high expediency in the synthesis of menaquinone [K2] analogue MK-6: Application to access an efficient one-pot protocol to MK-9
Yerramsetti, Nanaji,Dampanaboina, Lavanya,Mendu, Venugopal,Battula, Satyanarayana
, (2020/11/12)
Here we report a practical and efficient method for the synthesis of menaquinone vitamin (K2) analog MK-6 in all trans forms through “1 + 5 convergent synthetic approach” of pentaprenyl chloride with monoprenyl menadione derivative. In the synergistic factors, less efficient leaving group/more efficient nucleophile (Cl) in the substrate makes it more prominent reaction by eliminating all Sn2’ side reaction products. Further, the addition of acetic acid in the last step (desulfonation) of reaction sequence removes the limitations of the reactions in terms of cyclized side product (multiple reactions of pentaprenyl alcohol with Et3B), byproduct (Et3B, incendiary compound) formations and their interruption in the tricky purification processes. The utility of this method was further extended to find an efficient one-pot synthesis to MK-9 to the gram scale synthesis. This approach is economical and efficient and avoids the awkward chromatographic separation processes.
KMnO4-catalyzed chemoselective deprotection of acetate and controllable deacetylation-oxidation in one pot
Gurawa, Aakanksha,Kumar, Manoj,Rao, Dodla S.,Kashyap, Sudhir
supporting information, p. 16702 - 16707 (2020/10/27)
A novel and efficient protocol for chemoselective deacetylation under ambient conditions was developed using catalytic KMnO4. The stoichiometric use of KMnO4 highlighted the dual role of a heterogeneous oxidant enabling direct access to aromatic aldehydes in one-pot sequential deacetylation-oxidation. The reaction employed an alternative solvent system and allowed the clean transformation of benzyl acetate to sensitive aldehyde in a single step while preventing over-oxidation to acids. Use of inexpensive and readily accessible KMnO4 as an environmentally benign reagent and the ease of the reaction operation were particularly attractive, and enabled the controlled oxidation and facile cleavage of acetate in a preceding step. This journal is
