17094-21-2Relevant academic research and scientific papers
Prenylated β-diketones, two new additions to the family of biologically active Hypericum perforatum L. (Hypericaceae) secondary metabolites
Radulovi?, Niko S.,Gen?i?, Marija S.,Stojanovi?, Nikola M.,Randjelovi?, Pavle J.,Baldovini, Nicolas,Kurteva, Vanya
, p. 505 - 513 (2018)
Two novel β-diketones, 2,6,9-trimethyl-8-decene-3,5-dione (A) and 3,7,10-trimethyl-9-undecene-4,6-dione (B), were identified from the renowned medicinal plant Hypericum perforatum L. The structures of β-diketones A and B were corroborated by syntheses (4 steps starting from methyl acetoacetate, overall yields 30% and 23%, respectively). In solution, these β-diketones predominantly exist as two rapidly interconverting β-keto-enol tautomers. The structures of A and B show some common fragments with the molecules of hyperforin and adhyperforin, respectively, the acknowledged multi-target secondary metabolites from St. John's wort. It is therefore not surprising that A displayed a noteworthy biological activity profile as well (including brine shrimp toxicity, antinociceptive, antidepressant and acetylcholinesterase inhibitory activity). β-Diketone A manifested the most outstanding potency as an acetylcholinesterase inhibitor with IC50 value of 1.51 μM pointing again to the β-keto-enol moiety as a promising lead structure for the development of drugs that could lessen symptoms of Alzheimer's disease (such as dementia, depression and pain).
SAPONINS FROM STEM BARK OF PETERSIANTHUS MACROCARPUS
Massiot, Georges,Chen, Xiang-Fei,Lavaud, Catherine,Men-Olivier, Louisette le,Delaude, Clement,et al.
, p. 3571 - 3576 (1992)
Two bioactive saponins were isolated from the stem bark of Petersianthus macrocarpus.Their structures were elucidated by chemical degradations and by a combination of 2D NMR techniques and by Californium plasma desorption mass spectrometry.They are 3-O-2)>3)>-β-D-glucuronopyranosyl>-21-O- barringtogenol C and 3-O-2)>3)>-β-D-glucuronopyranosyl>-28-O-α-L-rhamnopyranosyl barringtogenol C-21-O-benzoate.The absolute configuration of nilic acid was determined by partial synthesis. 3,3'-Dimethoxy ellagic acid and 3,3'-dimethoxy-4-O-β-D-glucopyranosyl ellagic acid were also isolated.Key Word Index: Petersianthus macrocarpus; Lecythidaceae; bark; saponins; nilic acid; ellagic acid.
Total Synthesis of Oridamycins A and B
Trotta, Adam H.
, p. 3358 - 3361 (2015)
(Chemical Equation Presented) The total synthesis of both oridamycin A and oridamycin B was accomplished starting from a common synthetic intermediate readily prepared from geranyl acetate. The sequence utilizes an oxidative radical cyclization to construct the trans-decalin ring system, setting three of four contiguous stereocenters in one operation. The carbazole nucleus was forged through a one-pot process entailing acid-promoted dehydration followed by 6π-electrocyclization/aromatization.
Method for preparing pentazocine intermediate
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Paragraph 0029-0030; 0058-0061, (2021/02/13)
The invention belongs to the technical field of chemical synthesis, and provides a method for preparing a pentazocine intermediate, which comprises the following steps: by using low-price methyl acetoacetate as a raw material, carrying out methylation, methoxyformylation and removal of one methoxyformyl group, reducing by using a reducing agent, and reacting the reduction product with alkyl sulfonyl chloride to obtain the pentazocine intermediate; generating a compound with a dialkyl sulfonyl group; reacting a compound with dialkyl sulfonyl with phthalimide potassium salt, removing one alkyl sulfonyl, and grafting phthalimide; carrying out dehydrogenation reaction on the phthalimido product under an alkaline condition to generate a vinyl compound, and reacting the vinyl compound with hydrazine hydrate to obtain the pentazocine intermediate. Cheap compounds are used as initial raw materials, the whole route avoids high-pressure and high-temperature dangerous reactions, and industrial production is facilitated.
Catalytic Asymmetric Homologation of Ketones with α-Alkyl α-Diazo Esters
Tan, Fei,Pu, Maoping,He, Jun,Li, Jinzhao,Yang, Jian,Dong, Shunxi,Liu, Xiaohua,Wu, Yun-Dong,Feng, Xiaoming
supporting information, p. 2394 - 2402 (2021/02/16)
The homologation of ketones with diazo compounds is a useful strategy to synthesize one-carbon chain-extended acyclic ketones or ring-expanded cyclic ketones. However, the asymmetric homologation of acyclic ketones with α-diazo esters remains a challenge due to the lower reactivity and complicated selectivity. Herein, we report the enantioselective catalytic homologation of acetophenone and related derivatives with α-alkyl α-diazo esters utilizing a chiral scandium(III) N,N′-dioxide as the Lewis acid catalyst. This reaction supplies a highly chemo-, regio-, and enantioselective pathway for the synthesis of optically active β-keto esters with an all-carbon quaternary center through highly selective alkyl-group migration of the ketones. Moreover, the ring expansion of cyclic ketones was accomplished under slightly modified conditions, affording a series of enantioenriched cyclic β-keto esters. Density functional theory calculations have been carried out to elucidate the reaction pathway and possible working models that can explain the observed regio- and enantioselectivity.
Palladium Catalyzed Ring Expansion Reaction of Isoxazolones with Isocyanides: Synthesis of 1,3-Oxazin-6-One Derivatives
Zhu, Yi-Ming,Zhang, Wan,Li, Hongkun,Xu, Xiao-Ping,Ji, Shun-Jun
, p. 808 - 818 (2020/12/03)
A palladium catalyzed ring expansion reaction of isoxazolones with isocyanides was disclosed. In the reaction, a cascade process involving ring-opening/cyclization was suggested. The reaction features high atomic economy due to no elimination of CO2 occurred. Moreover, products obtained demonstrate aggregation-induced emission properties with relatively high solid-state emission efficiencies. (Figure presented.).
Synthesis method of pirimicarb intermediate 2-methyl acetoacetate
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Paragraph 0040; 0044-0047; 0050-0052; 0055-0057; 0060-0062, (2020/12/10)
The invention relates to a synthesis method of a pirimicarb intermediate 2-methyl acetoacetate, comprising the following steps of: in the presence of tertiary amine and a polymerization inhibitor, carrying out an addition reaction on raw materials methyl acrylate and acetyl chloride to obtain 2-acetyl-methyl acrylate, and carrying out hydrogenation reduction to obtain the product 2-methyl acetoacetate. The synthetic method of the pirimicarb intermediate 2-methyl acetoacetate has the advantages of high yield, high purity and few byproducts.
Iron-Catalyzed Carbene Insertion Reactions of α-Diazoesters into Si-H Bonds
Keipour, Hoda,Ollevier, Thierry
supporting information, p. 5736 - 5739 (2017/11/10)
An efficient iron-catalyzed carbene insertion reaction of α-diazo carbonyl compounds into the Si-H bond was developed. A wide range of α-silylesters was obtained in high yields (up to 99%) from α-diazoesters using a simple iron(II) salt as catalyst.
Enantioselective Palladium-Catalyzed Carbene Insertion into the N?H Bonds of Aromatic Heterocycles
Arredondo, Vanessa,Hiew, Stanley C.,Gutman, Eugene S.,Premachandra, Ilandari Dewage Udara Anulal,Van Vranken, David L.
supporting information, p. 4156 - 4159 (2017/04/03)
C3-substituted indoles and carbazoles react with α-aryl-α-diazoesters under palladium catalysis to form α-(N-indolyl)-α-arylesters and α-(N-carbazolyl)-α-arylesters. The products result from insertion of a palladium-carbene ligand into the N?H bond of the aromatic N-heterocycles. Enantioselection was achieved using a chiral bis(oxazoline) ligand, in many cases with high enantioselectivity (up to 99 % ee). The method was applied to synthesize the core of a bioactive carbazole derivative in a concise manner.
Synthesis method of 2-methyl methyl acetoacetate for pesticide production
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Paragraph 0011; 0012; 0013; 0014, (2017/08/27)
The invention discloses a synthesis method of 2-methyl methyl acetoacetate for pesticide production. By means of matching of methyl acetoacetate, palladium on carbon, acetic acid and pyridine, the recovery rate of methyl acetoacetate can be increased while the reaction rate is proper; through control over the ratio of formaldehyde to methyl acetoacetate, the recovery rate of methyl acetoacetate can be increased while quality is guaranteed; through control over the adding time of formaldehyde, the yield of products can be increased, filtered palladium on carbon is recycled, the production cost can be reduced, the vacuum degree ranges from 1,330 Pa to 2,660 Pa, and the effect of reduced pressure distillation can be improved. 2-methyl methyl acetoacetate synthesized through the synthesis method has the advantages of being high in yield and low in cost, market potential is large, and prospects are wide.
