58081-05-3Relevant articles and documents
Inversion of configuration of (S)-β-hydroxy-γ-butyrolactone with total retention of the enantiomeric purity
De Angelis, Francesco,De Fusco, Enrico,Desiderio, Paola,Giannessi, Fabio,Piccirilli, Fabrizio,Tinti, Maria Ornella
, p. 2705 - 2707 (1999)
In this paper we report the inversion of configuration of (S)β-hydroxy- γ-butyrolactone [(S)-1] to its (R) enantiomer (R)-1, with total retention of the enantiomeric purity, by a four-step procedure. The (R)-β-hydroxy-γ- butyrolactone [(R)-1] was thus synthetized with an overall chemical yield of 47% and > 97% ee. This transformation opens an economic route to the production of (R)-GABOB and (R)-carnitine, among other biologically active compounds, from a D-hexose source, or, alternatively, from the industrial waste compound (S)carnitine. During the reaction sequence, the intermediate β-lactone 4 is also prepared, which is now under investigation as a chiral synthon for new synthetic applications.
Ru/SiO2 Catalyst for Highly Selective Hydrogenation of Dimethyl Malate to 1,2,4-Butanetriol at Low Temperatures in Aqueous Solvent
Chen, Can,Jiang, Junxiang,Li, Guangci,Li, Xuebing,Wang, Da,Wang, Zhong,Yu, Pei
, (2022/01/12)
Catalytic selective hydrogenation of esterified malic acid to produce 1,2,4-butanetriol (1,2,4-BT) using H2 as the reducing reagent suffers from the low 1,2,4-BT selectivity. Here, Ru/SiO2 catalyst was employed for selective hydrogenation of dimethyl malate (DM) to produce 1,2,4-BT, which gave abnormal high DM conversion (100%) and 1,2,4-BT selectivity (92.4%) in aqueous solvent at 363?K, especially, the 1,2,4-BT yield even is higher than the optimal catalyst reported (Ru-Re, 79.8%). The reaction pathways for the DM hydrogenation on Ru/SiO2 were also proposed, suggesting that extremely high 1,2,4-BT selectivity require for the much high hydrogenation rates at low temperatures, where side-reaction transesterification rates are relatively low. The extremely high hydrogenation activity and 1,2,4-BT selectivity on Ru/SiO2 in aqueous solvent at low temperatures arise from that H2O may coordinate to Ru2+ and prevent the reduction of Ru2+ to Ru under high H2 pressure. Ru/SiO2 surface presents abundant Ru2+ in aqueous solvent, can activate H2 through heterolytic cleavage mode to form hydride, which can significantly increase hydrogenation rates of C = O groups at low temperatures. In addition, the activity and 1,2,4-BT selectivity on Ru/SiO2 catalyst only reduced by 2.3% and 2.6%, respectively over a period of 550?h. Graphical Abstract: [Figure not available: see fulltext.]
A Concise Stereoselective Total Synthesis of Methoxyl Citreochlorols and Their Structural Revisions
Sunnapu, Ranganayakulu,Rajendar, Goreti
, p. 1637 - 1642 (2021/03/15)
A concise, stereoselective and protecting group free approaches for the total synthesis of (?)-(2S,4R)- and (+)-(2R,4S)-3′-methoxyl citreochlorols and their stereoisomers are demonstrated. All four stereoisomers were synthesized to establish the absolute stereochemistry of the reported structures and the structures were revised accordingly. The approach involves chelation controlled regioselective reduction of a diester, silyl iodide promoted ring-opening iodo esterification of lactones, highly chemo- and regioselective ring-opening of an epoxy ester, dichloromethylation of a carboxyl group, and syn- and anti-selective reduction of the resulted β-hydroxy ketone as key steps.
Synthesis of nature product kinsenoside analogues with anti-inflammatory activity
Song, Wei,Sun, Yong,Xu, Lintao,Sun, Yajing,Li, Tianlu,Peng, Peng,Lou, Hongxiang
supporting information, (2020/12/02)
Kinsenoside is the major bioactive component from herbal medicine with a broad range of pharmacological functions. Goodyeroside A, an epimer of kinsenoside, remains less explored. In this report we chemically synthesized kinsenoside, goodyeroside A and their analogues with glycan variation, chirality inversion at chiral center(s), and bioisosteric replacement of lactone with lactam. Among these compounds, goodyeroside A and its mannosyl counterpart demonstrated superior anti-inflammatory efficacy. Furthermore, goodyeroside A was found to suppresses inflammatory through inhibiting NF-κB signal pathway, effectively. Structure-activity relationship is also explored for further development of more promising kinsenoside analogues as drug candidates.
Azo aryl urea derivative, and preparation method and application thereof
-
Paragraph 0161-0162; 0164-0165, (2020/06/17)
The invention relates to an azo aryl urea derivative, and a preparation and an application thereof, and concretely discloses a compound represented by formula (I), or an optical isomer, a cis-trans-isomer or a pharmaceutically acceptable salt thereof, and a preparation method thereof. Definitions of substituent groups in the general formula are described in the specification and claims. The invention further discloses a composition containing the above compound, and an application thereof. The compound has excellent anticancer activity on HepG2 liver cancer cells, MGC803 gastric cancer cells,HCT116 colon cancer and the like.
Synthesis method of R-3-propyl-gamma-butyrolactone
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Paragraph 0042; 0045-0048, (2020/07/12)
The invention discloses a synthetic method of R-3-propyl-gamma-butyrolactone, and belongs to the technical field of organic synthesis. The method comprises the following steps: by taking D-malic acidas a raw material, performing monomethyl esterification, reduction, halogenation or sulfonic acid esterification, and finally coupling with a Grignard reagent under the catalysis of zinc chloride to obtain a brivaracetam intermediate that is the R-3-propyl-gamma-butyrolactone. The method has the advantages of cheap and easily available starting raw materials, good stereoselectivity, no need of chiral resolution, mild condition, short route and the like, and provides a feasible scheme for brivaracetam process research.
Stereoselective Cobalt-Catalyzed Cross-Coupling Reactions of Arylzinc Chlorides with α-Bromolactones and Related Derivatives
Hofmayer, Maximilian S.,Sunagatullina, Alisa,Br?samlen, Daniel,Mauker, Philipp,Knochel, Paul
supporting information, p. 1286 - 1289 (2020/02/13)
α-Bromolactones bearing a substituent in the β-position undergo a highly trans-diastereoselective arylation with arylzinc chlorides in the presence of 10-20% CoCl2 and 10-20% PPh3 in THF under mild conditions (25 °C, 16 h) leading to
Practical Cleavage of Acetals by Using an Odorless Thiol Immobilized on Silica
de Léséleuc, Mylène,Kukor, Andrew,Abbott, Shaun D.,Zacharie, Boulos
, p. 7389 - 7393 (2019/12/03)
A practical, efficient and general method was developed for the deprotection of a variety of aromatic and aliphatic acetals to their corresponding catechol or diol derivatives using thiol immobilized on silica gel. This is an application for the well-known commercial solid-supported thiol (SiliaMetS Thiol). The procedure is mild and amenable to scale-up. It does not require inert atmosphere and clean conversions were observed. This method is applicable to substituted 1,3-benzodioxole and aliphatic acetals with different functionalities. It offers the advantage of a general route with high yield, which can be undertaken at ambient temperature.
Intercepted dehomologation of aldoses by N-heterocyclic carbene catalysis-a novel transformation in carbohydrate chemistry
Draskovits, Markus,Kalaus, Hubert,Stanetty, Christian,Mihovilovic, Marko D.
, p. 12144 - 12147 (2019/10/21)
The development of an N-heterocyclic carbene (NHC) catalysed intercepted dehomologation of aldoses is reported. The unique selectivity of NHCs for aldehydes is exploited in the complex context of reducing sugars. Examples of strong substrate governance for either intercepted dehomologation or a subsequent redox-lactonisation were identified and mechanistically understood. More importantly, it was shown that catalyst design allowed the tuning of the selectivity of the reaction with structurally unbiased starting materials towards either of the two scenarios.
Total synthesis and stereochemical assignment of nostosin B
Wang, Xiaoji,Feng, Junmin,Xu, Zhengshuang,Ye, Tao,Meng, Yi,Zhang, Zhiyu
, (2017/04/06)
Nostosins A and B were isolated from a hydrophilic extract of Nostoc sp. strain from Iran, which exhibits excellent trypsin inhibitory activity. Nostosin A was the most potent natural tripeptide aldehyde as trypsin inhibitor up to now. Both R- and S-2-hydroxy-4-(4-hydroxy-phenyl)butanoic acid (Hhpba) were prepared and incorporated into the total synthesis of nostosin B, respectively. Careful comparison of the NMR spectra and optical rotation data of synthetic nostosin B (1a and 1b) with the natural product led to the unambiguous identification of the R-configuration of the Hhpba fragment, which was further confirmed by co-injection with the authentic sample on HPLC using both reversed phase column and the chiral AD-RH column.
