28010-12-0Relevant articles and documents
HPLC and GC-MS identification of the major organic constituents in New Zealand propolis
Markham, Kenneth R.,Mitchell, Kevin A.,Wilkins, Alistair L.,Daldy, Julia A.,Lu, Yinrong
, p. 205 - 211 (1996)
The major organic constituents of New Zealand sourced propolis have been identified and quantified in tincture solutions by a combination of HPLC and GC-mass spectrometry (MS). HPLC was the preferred method for the analysis of flavonoids because of their very low response factors in GC-MS. Flavonoid levels ranged from 30-40 mg ml-1. A distinctive characteristic of the flavonoids in New Zealand propolis is the unusually high proportion (ca 70%) of dihydroflavonoids, e.g. pinocembrin, pinobanksin and pinobanksin 3-acetate. Non-flavonoid components analysed by GC-MS comprised a range of aromatic compounds (3-7.5 mg ml-1), together with low levels (0.25-0.78 mg ml-1) of fatty acids. The former comprised mainly cinnamic acids and their esters, but also included the rare 5-phenyl-trans-trans-2,4-pentadienoic acid and the new natural product, 5-phenyl-trans-3-pentenoic acid. Both were synthesized to confirm their identity. Copyright
Ghosh et al.
, p. 2771,2775 (1930)
Stereoregular two-dimensional polymers constructed by topochemical polymerization
Wang, Zhihan,Randazzo, Katelyn,Hou, Xiaodong,Simpson, Jeffrey,Struppe, Jochem,Ugrinov, Angel,Kastern, Brent,Wysocki, Erin,Chu, Qianli R.
, p. 2894 - 2900 (2015)
Two stereoregular 2D polyesters were synthesized by using topochemical polymerization of symmetric four-armed monomers. The monomers contain reactive carbon-carbon double bond(s) on each arm. The critical assemblies with multiple preorganized reactive centers were characterized by powder and single crystal X-ray diffraction. The solvent-free polymerization could be carried out with sunlight or UV irradiation. The locally confined photopolymerization process dimerized all of the olefins within the 2D bricklayer packing, which led to the formation of 2D polymers in the solid state. The process was monitored by FT-IR, and the products were confirmed by solid state NMR. After hydrolysis of the 2D polyester, the newly formed carbon-carbon single bonds during the [2 + 2] photocyclization were directly revealed by the single crystal structure of the hydrolysis product. Ultrathin sheets of the 2D polymer were observed under SEM and TEM after exfoliation.
Photo-Promoted Decarboxylative Alkylation of α, β-Unsaturated Carboxylic Acids with ICH2CN for the Synthesis of β, γ-Unsaturated Nitriles
Pan, Chunxiang,Yang, Chunhui,Li, Kangkui,Zhang, Keyang,Zhu, Yuanbin,Wu, Shiyuan,Zhou, Yongyun,Fan, Baomin
supporting information, p. 7188 - 7193 (2021/10/01)
An efficient, catalyst/photocatalyst-free, and cost-effective methodology for the decarboxylative alkylation of α,β-unsaturated carboxylic acids to synthesize β,γ-unsaturated nitriles has been developed. The reaction proceeded in an environmentally benign atmosphere of blue light-emitting diode irradiation with K2CO3 and water at room temperature. The methodology worked for a wide range of substrates (22 examples) with up to 83% yield. The protocol is also compatible for gram-scale synthesis.
Reaction of 5-phenylpenta-2,4-dienoic acid with benzene in trifluoromethanesulfonic acid
Ismagilova, A. R.,Osetrova, L. V.,Vasilyev, A. V.,Zakusilo, D. N.
, p. 1928 - 1932 (2020/11/05)
The reaction of 5-phenylpenta-2,4-dienoic acid with benzene in CF3SO3H, depending on the reaction conditions, gives three products, namely, 5,5-diphenylpent-2-enoic acid and tetralone and indanone derivatives. These carbocyclic compo
