6622-76-0Relevant articles and documents
Lewis Acid Catalysis of the Ene Addition of Chloral and Bromal to Olefins; Stereochemical and Mechanistic Studies
Benner, Jill P.,Gill, G. Bryon,Parrott, Stephen J.,Wallace, Brian,Begley, Michael J.
, p. 315 - 329 (1984)
The Lewis acid catalysed ene additions of chloral and bromal to alkenes are completely regiospecific, moderately regioselective, and often highly stereoselective.Diastereoselectivity in the addition to (-)-β-pinene was a function of the Lewis acid, and with TiCl4 essentially quantitative asymmetric induction was observed.The stereochemical phenomena are explained satisfactory by assuming the active enophiles possess transoid structures such as (1), that a concerted or rapid stepwise mechanism operates, and that product formation occurs predominantly through the least hindered encounter complex of the olefin and (1).In the case of 2-methylbut-2-ene, however, there is some evidence for an additional stereoelectronic contribution, the 'cis-effect'.Stereochemical assignements are supported by X-ray structural data.Ketones, hydrohalogenated ene adducts, or rearrangement products are formed (mainly in the addition to olefins of moderate reactivity) indicating the participation of Friedel-Crafts type dipolar intermediates.The ene adducts themselves could be formed via dipolar intermediates or in competing 'concerted' reactions; the stepwise mechanism must operate in some reactions because of the observation of Wagner-Meerwein rearrangements.Olefin reactivity over the series, measured by the competitive technique, towards chloral-AlCl3 showed a ca. 900-fold variation in rate; 'ene' reactivity decreases more steeply.
Gastric cytoprotective activity of 2-cyclopenten-1-one and related compounds
Maria,Wendel,Guardia,Guzman,Pestchanker,Guerreiro,Giordano
, p. 1784 - 1786 (1995)
The cytoprotective activity of the isolated functional groups of several sesquiterpene lactones is reported. Among them the highest activity is shown by α-methylen-γ-butyrolactone and 2-cyclopenten-1-one. The activity shown by those Michael acceptors with a β carbon hindered by an alkyl substituent was always lower or almost null. A three-way mechanism of action is proposed: a) reduced glutathione synthesis, b) prostaglandin synthesis and c) mucosal glycoprotein synthesis.
Second-Generation meta-Phenolsulfonic Acid-Formaldehyde Resin as a Catalyst for Continuous-Flow Esterification
Hu, Hao,Ota, Hajime,Baek, Heeyoel,Shinohara, Kenta,Mase, Toshiaki,Uozumi, Yasuhiro,Yamada, Yoichi M. A.
supporting information, p. 160 - 163 (2020/01/02)
A second-generation m-phenolsulfonic acid-formaldehyde resin (PAFR II) catalyst was prepared by condensation polymerization of sodium m-phenolsulfonate and paraformaldehyde in an aqueous H2SO4 solution. This reusable, robust acid resin catalyst was improved in both catalytic activity and stability, maintaining the characteristics of the previous generation catalyst (p-phenolsulfonic acid-formaldehyde resin). PAFR II was applied in the batchwise and continuous-flow direct esterification without water removal and provided higher product yields in continuous-flow esterification than any other commercial ion-exchanged acid catalyst tested.
BIPOLAR TRANS CAROTENOID SALTS AND USES THEREOF
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Paragraph 0083; 0134; 0188, (2018/10/26)
PROBLEM TO BE SOLVED: To provide compounds useful in improving diffusivity of oxygen between red blood cells and body tissues in mammals including humans. SOLUTION: There is provided a compound which has a structure represented by YZ-TCRO-ZY and is not trans sodium crocetinate [where, Y is a cation; Z is a polar group which is associated with the cation; and TCRO is trans carotenoid skeleton], and preferably, Y is a monovalent metal ion selected from the group consisting of Na+, K+ and Li+, or is an organic cation selected from the group consisting of R4 N+ and R3S+ [R is H, or CnH2n+1(n is 1 to 10)]. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPO&INPIT
3-PHOSPHOGLYCERATE DEHYDROGENASE INHIBITORS AND USES THEREOF
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Paragraph 00429, (2017/10/06)
The present invention provides compounds, compositions thereof, and methods of using the same.