505-90-8Relevant articles and documents
Bioactive constituents from the leaves of Croton tiglium
Duan, Li-Kun,Feng, Jin-E.,He, Hong-Ping,Huang, Chun-Qiu,Jiang, Zhi-Yong,Li, Xiao-Fei,Li, Yuan,Liu, Chun-Jiang,Shi, Sheng-Li,Zuo, Ai-Xue
, p. 65 - 72 (2022/03/15)
Fifteen compounds, including five new phorbol esters (1-5) and ten known metabolites were isolated from the leaves of Croton tiglium. The structures of new compounds 1-5 were determined by comprehensive analysis of the HRESIMS, IR, 1D and 2D NMR spectral
Bidentate auxiliary-directed alkenyl C-H allylation: Via exo-palladacycles: Synthesis of branched 1,4-dienes
Shen, Cong,Lu, Xiunan,Zhang, Jian,Ding, Liyuan,Sun, Yaling,Zhong, Guofu
, p. 13582 - 13585 (2019/11/14)
An alkenyl C-H allylation by an exo-palladacycle intermediate is demonstrated, employing unactivated (Z)-Alkenes and allyl carbonates. With the use of an 8-Aminoquinoline (AQ) derived amide as the directing group, the N,N-bidentate-chelation-Assisted C-H activation protocol proceeded under mild and oxidant-free conditions with excellent selectivity. The utility of this approach is demonstrated by the preparative scale, selective conversion of inseparable Z/E alkenes and ready removal of the amide auxiliary to provide the corresponding ester.
Alkenyl Carbonyl Derivatives in Enantioselective Redox Relay Heck Reactions: Accessing α,β-Unsaturated Systems
Zhang, Chun,Santiago, Celine B.,Kou, Lei,Sigman, Matthew S.
supporting information, p. 7290 - 7293 (2015/06/30)
A highly enantioselective and site-selective Pd-catalyzed arylation of alkenes linked to carbonyl derivatives to yield α,β-unsaturated systems is reported. The high site selectivity is attributed to both a solvent effect and the polarized nature of the carbonyl group, both of which have been analyzed through multidimensional analysis tools. The reaction can be performed in an iterative fashion allowing for a diastereoselective installation of two aryl groups along an alkyl chain.
(Z)-N-(4-Decenoyl)homoserine lactone, a new quorum-sensing molecule, produced by endobacteria associated with Mortierella alpina A-178
Kai, Kenji,Kasamatsu, Koji,Hayashi, Hideo
, p. 5441 - 5444 (2012/10/30)
N-Acylhomoserine lactones (AHLs) are the conserved quorum-sensing signal molecules in Gram-negative bacteria. (Z)-N-(4-Decenoyl)homoserine lactone (1), a new AHL, was isolated from the culture broth of the fungus Mortierella alpina A-178 harboring bacterial endosymbionts, called endobacteria. The structure and absolute configuration of 1 were elucidated by EI-MS, chemical synthesis, and chiral GC analysis. The compound induced the expression of a QS-regulated reporter gene in Agrobacterium tumefaciens NTL4, although its activity was lower than that of N-decanoylhomoserine lactone (6).
TPAP-catalyzed direct oxidation of primary alcohols to carboxylic acids through stabilized aldehyde hydrates
Schmidt, Andrea-Katharina C.,Stark, Christian B. W.
supporting information; experimental part, p. 4164 - 4167 (2011/10/08)
We present a simple, mild, and highly effective method for the direct conversion of primary alcohols to carboxylic acids. TPAP serves as the catalyst, and NMO?H2O plays a dual role, acting as the co-oxidant and as a reagent for aldehyde hydrate stabilization. This previously unknown stabilizing effect of geminal diols by N-oxides is the key for the efficiency of the overall transformation.
Synthesis and characterization of cis-4-decenoyl-CoA, 3-phenylpropionyl-CoA, and 2,6-dimethylheptanoyl-CoA
Sobhi, Hany F.,Minkler, Paul E.,Hoppel, Charles L.
experimental part, p. 114 - 124 (2011/10/30)
The measurement of acyl-CoA dehydrogenase activities is an essential part of the investigation of patients with suspected defects in fatty acid oxidation. Multiple methods are available for the synthesis of the substrates used for measuring acyl-CoA dehydrogenase activities; however, the yields are low and the products are used without purification. In addition, the reported characterization of acyl-CoAs focuses on the CoA moiety, not on the acyl group. Here we describe the synthesis of three medium-chain acyl-CoAs from mixed anhydrides of the fatty acids using an aqueous-organic solvent mixture optimized to obtain the highest yield. First, cis-4-decenoic acid and 2,6-dimethylheptanoic acid were prepared (3-phenylpropionic acid is commercially available). These were characterized by gas chromatography/mass spectrometry (GC/MS), 1H nuclear magnetic resonance (NMR), and 13C NMR. Then cis-4-decenoyl-CoA, 3-phenylpropionyl-CoA, and 2,6-dimethylheptanoyl-CoA were synthesized. These were then purified by ion exchange solid-phase extraction using 2-(2-pyridyl)ethyl-functionalized silica gel, followed by reversed-phase semipreparative high-performance liquid chromatography with ultraviolet detection (HPLC-UV). The purified acyl-CoAs were characterized by analytical HPLC-UV followed by data-dependent tandem mass spectrometry (MS/MS) analysis on the largest responding MS mass (HPLC-UV-MS-MS/MS) and 13C NMR. The yields of the purified acyl-CoAs were between 75% and 78% based on coenzyme A trilithium salt (CoASH). Acyl-CoA dehydrogenase activities were measured in rat skeletal muscle mitochondria using, as substrates, the synthesized cis-4-decenoyl-CoA, 3-phenylpropionyl-CoA, and 2,6-dimethylheptanoyl-CoA. These results were compared with the results using our standard substrates butyryl-CoA, octanoyl-CoA, and palmitoyl-CoA.
Enantioselective epoxidation of nonconjugated cis-olefins by chiral dioxirane
Burke, Christopher P.,Shi, Yian
supporting information; experimental part, p. 5150 - 5153 (2009/12/28)
A variety of nonconjugated cis-olefins has been enantioselectively epoxidized with chiral ketones 2, and up to 92% ee has been obtained. The two prochiral faces of an olefin are likely stereodifferentiated by the relative hydrophobicity of the olefin substituents and/or allylic oxygen functionality.
Composition of the cloacal gland secretion of tuatara, Sphenodon punctatus
Flachsbarth, Birte,Fritzsche, Matthias,Weldon, Paul J.,Schulz, Stefan
experimental part, p. 1 - 37 (2010/04/23)
The lipophilic content of the cloacal gland secretion of the tuatara (Sphenodon punctatus) was investigated. GC/EI-MS Analysis of CH2Cl2 extracts of the secretions revealed triacylglycerols as major glandular constituents. Twelve major medium-chain fatty acids were found to be conjugated to glycerol in different combinations, resulting in complex mixtures. These acids were identified by transesterification and subsequent derivatization of natural samples, and their structures were verified by synthesis. The natural glycerides contain predominantly three of the following acids: octanoic (A), (E)- and (Z)-oct-4-enoic (B and C, resp.), (4E,6Z)-octa-4,6-dienoic (tuataric acid;D), (R)-2,6-dimethylheptanoic (E), (R)-2,6-dimethylhept-5-enoic (F), (Z)-dec-4-enoic (G), (4Z,7Z)-deca-4,7-dienoic (H), (R)-3,7-dimethyloct-6-enoic (I), (R)-4,8-dimethylnon-7-enoic (J), (2R,6S)-2,6,10-trimethylundec-9-enoic (K), and (2R,5E)-2,6,10-trimethylundeca-5,9-dienoic acids (L). Several additional acids, occurring in trace amounts only, were tentatively identified by MS. The elucidation of the absolute configuration of the acids was performed by GC on chiral phases. Individual tuatara show specific mixtures of glycerides with up to 100 components. The individual mixtures may permit individual recognition because the bouquets seem to be stable over years.
Catalytic osmium-assisted oxidative cleavage of olefins
-
, (2008/06/13)
An osmium-assisted process for the oxidative cleavage of oxidizable organic compounds such as unsaturated organic compounds, including alkenes and olefins into aldehydes, carboxylic acids, esters, or ketones. The process uses a metal catalyst comprising osmium and a peroxy compound selected from the group consisting of peroxymonosulfuric acid and salts thereof to oxidatively cleave the oxidizable organic compound. In particular, the process enables aldehydes, carboxylic acids, esters, or ketones to be selectively produced from the corresponding mono-, 1,1-di-, 1,2-di-, tri-, or tetra-substituted olefins in a reaction that produces the result of ozonolysis but with fewer problems. The present invention further provides a process for oxidizing an aldehyde alone or with the osmium in an interactive solvent to produce an ester or carboxylic acid.
IBX-mediated oxidation of primary alcohols and aldehydes to form carboxylic acids
Mazitschek, Ralph,Muelbaier, Marcel,Giannis, Athanassios
, p. 4059 - 4061 (2007/10/03)
Under mild conditions and without the use of toxic metals, the oxidation of primary alcohols and aldehydes to the corresponding carboxylic acids with 1-hydroxy-1,2-benziodoxole-3(1H)-one-1-oxide (IBX) proceeds in the presence of 1-hydroxypyridine or N-hydroxysuccinimide (see scheme). The reaction tolerates a wide variety of functional groups.