108350-21-6Relevant articles and documents
An efficient procedure for the synthesis of formylacetic esters
Edvinsson, Sofie,Johansson, Susanne,Larsson, Andreas
, p. 6819 - 6821 (2012)
An efficient synthesis of formylacetic esters via ozonolysis of trans-β-hydromuconic esters followed by a solid-supported triphenylphosphine reduction has been developed. In addition, an extension toward formylacetic amides and a one-pot preparation of more stable intermediates which can be used for further transformations are also described.
A Peptoid with Extended Shape in Water
Morimoto, Jumpei,Fukuda, Yasuhiro,Kuroda, Daisuke,Watanabe, Takumu,Yoshida, Fumihiko,Asada, Mizue,Nakamura, Toshikazu,Senoo, Akinobu,Nagatoishi, Satoru,Tsumoto, Kouhei,Sando, Shinsuke
, p. 14612 - 14623 (2019)
The term "peptoids" was introduced decades ago to describe peptide analogues that exhibit better physicochemical and pharmacokinetic properties than peptides. Oligo(N-substituted glycine) (oligo-NSG) was previously proposed as a peptoid due to its high proteolytic resistance and membrane permeability. However, oligo-NSG is conformationally flexible, and ensuring a defined shape in water is difficult. This conformational flexibility severely limits the biological application of oligo-NSG. Here, we propose oligo(N-substituted alanine) (oligo-NSA) as a peptoid that forms a defined shape in water. The synthetic method established in this study enabled the first isolation and conformational study of optically pure oligo-NSA. Computational simulations, crystallographic studies, and spectroscopic analysis demonstrated the well-defined extended shape of oligo-NSA realized by backbone steric effects. This new class of peptoid achieves the constrained conformation without any assistance of N-substituents and serves as a scaffold for displaying functional groups in well-defined three-dimensional space in water, which leads to effective biomolecular recognition.
Scope and diastereoselectivity of the interrupted Feist-Benary reaction.
Calter, Michael A,Zhu, Cheng
, p. 205 - 208 (2002)
[reaction: see text] The base-promoted condensation of beta-dicarbonyl compounds with alpha-haloketones, the Feist-Benary reaction, conveniently produces highly substituted dihydrofurans. We show here that this reaction is quite general with respect to the nature of the beta-dicarbonyl compound, proceeding with beta-ketoesters, beta-oxopropionates, beta-diketones, and beta-dialdehydes. We also show that the diastereoselectivity of this reaction depends on the acidity of the nucleophile.
Orthogonally Protected Diaminoterephthalate Scaffolds: Installation of Two Functional Units at the Chromophore
Buschbeck, Leon,Christoffers, Jens
, p. 4002 - 4014 (2018/04/14)
The 2,5-diaminoterephthalate structural motif is a powerful chromophore with remarkable fluorescence properties. Containing two carboxylate and two amino functions, it defines a colored molecular scaffold which allows for orthogonal functionalization with different functional units. Therefore, different applications in life sciences and materials science could be addressed. In this study, the two amino functions were alkylated by reductive amination with side chains carrying amino (orthogonally protected as Boc or Alloc) and carboxylate functions (orthogonally protected as tBu or allyl ester). After sequential deprotections, functional units were introduced by amidation reactions. As three examples, the chromophore was coupled with retinoic acid and fullerene C60 in order to obtain a triad for studying photoinduced electron transfer processes. Furthermore, cyclooctyne and azide moieties were introduced as functional units, allowing for ligation by click reactions. These two clickable groups were applied in combination with maleimide units which are reactive toward thiol residues. The latter dyes define so-called turn on probes, since the fluorescence quantum yields increased by one order of magnitude upon reaction with the molecular target.
NHC catalyzed enantioselective Coates-Claisen rearrangement: A rapid access to the dihydropyran core for oleuropein based secoiridoids
Vedachalam, Seenuvasan,Murugesh, Nithya,Chakraborty, Priyanka,Karvembu, Ramasamy,Liu, Xue-Wei
supporting information, p. 1832 - 1839 (2018/02/09)
We present the short synthesis of the suitably functionalized enantioselective dihydropyran core of secoiridoids using an N-heterocyclic carbene (NHC) catalyzed Coates-Claisen rearrangement mechanism. The key steps of the synthesis are (i) the highly enantioselective NHC catalyzed Coates-Claisen rearrangement for the dihydropyran core, (ii) the assembly of the target dihydropyran core structure of oleuropein from a highly diastereoselective exocyclic trans alkene, and (iii) the highly stereoselective assembly of a monoterpene elenolide core structure.
Investigation on the chemoenzymatic synthesis of threo- and erythro-β-hydroxy-L-glutamic acid derivatives
Sagui, Francesca,De Micheli, Carlo,Roda, Gabriella,Magrone, Pietro,Pizzoli, Rachele,Riva, Sergio
experimental part, p. 27 - 34 (2012/04/10)
A derivative of the malonic semialdehyde was transformed by means of a bioconversion catalyzed by the enzyme L-threonine aldolase from E. coli into a 6:4 epimeric mixture of two precursors of β-hydroxy glutamic acid. The enzyme was selective for the formation of the (S)-configuration at C-2, whereas the configuration at C-3 was not controlled. The two epimers were separated exploiting a diastereoselective acylation in organic solvent catalyzed by lipase PS. The relative and absolute configurations of the products were preliminarily assigned on the base of the model proposed by Kazslauskas for the stereopreference of lipase PS and by comparison of the chemical shifts of the H-2 and H-3 protons of the two homologues. The possibility of transforming the obtained products into β-hydroxy glutamic acid derivatives by conventional chemical reactions was demonstrated.
Synthesis of Functionalized Azomethine Ylides via the Rh(II)-Catalyzed Cyclization of α-Diazo Carbonyls onto Imino ?-Bonds
Padwa, Albert,Dean, Dennis C.,Osterhout, Martin H.,Precedo, Laura,Semones, Mark A.
, p. 5347 - 5357 (2007/10/02)
α-Diazo carbonyl compounds containing an imino group in the γ-position have been found to undergo a rhodium(II) acetate induced cyclization reaction to generate cyclic azomethine ylides.The reactive dipole undergoes a subsequent 1,3-dipolar cycloaddition
SYNTHESIS OF 1,3-DIOXIN-4-ONES AND THEIR USE IN SYNTHESIS. XVI. 4-OXO-1,3-DIOXIN-5-CARBOXYLIC ACIDS AND RELATED COMPOUNDS: VERSATILE INTERMEDIATES FOR THE SYNTHESIS OF 6-UNSUBSTITUTED SIX-MEMBERED HETEROCYCLIC COMPOUNDS
Sato, Masayuki,Katagiri, Nobuya,Takayama, Kazuhisa,Hirose, Masatoshi,Kaneko, Chikara
, p. 665 - 669 (2007/10/02)
A novel method for the synthesis of so far unknown 1,3-dioxin-4-ones having a carboxyl group at the 5-position is described.Reaction of formyl Meldrum's acid and an alcohol in an aprotic solvent at 50-60 deg C gave the corresponding half esters of formylmalonic acid.Treatment of the latter with appropriate ketones in acetic anhydride containing a catalytic amount of p-toluenesulfonic acid gave the desired dioxinone-5-carboxylates.Successful conversion of these 1,3-dioxin-4-ones either to 1,3-oxazine-2,4-dione or uracil derivatives having an alkoxycarbonyl group at the 5-position demonstrated that these dioxinones can serve as chemical equivalents for alkoxycarbonylformylketenes.The fact that 5-benzyloxycarbonyl-1,3-dioxin-4-one can readily be transformed to the so far unknown 5-aminodioxinone derivative indicates further the importance of the dioxinone having a carboxyl group at the 5-position as a new building block for heterocyclic compounds.Keywords: 4-oxo-1,3-dioxin-5-carboxylic acid; formylmalonic acid half ester; Meldrum's acid; 5-amino-1,3-dioxin-4-one; cycloaddition; 4-oxo-1,3-oxazine-5-carboxylate; 2-dimethylamino-1,3-oxazin-4-one; alkoxycarbonylformylketene
Studies on Amino Acid Derivatives. Part 7. General Method for the Synthesis of Penam and Cepham and Their Substituted Derivatives
Chiba, Takuo,Sakaki, Jun-ichi,Takahashi, Takumi,Aoki, Kumi,Kamiyama, Akiko,et al.
, p. 1845 - 1852 (2007/10/02)
Penam (7-oxo-4-thia-1-azabicycloheptane), a basic skeleton of penicillin-type β-lactams, has been synthesized as a stable compound from thiazolidinylacetic acid.The key step in this synthesis is the formation of the β-lactam ring by Mukaiyama-Ohno's procedure.Three methods are developed for the synthesis of thiazolidinylacetic acid from cysteamine by reactions with ethyl propiolate, ethyl ethoxycarbonylacetimidate, or t-butyl formylacetate.Using appropriate derivatives of the latter compounds, 5-, 6-, and 5,6-substituted derivatives of penam are also synthesized.The yields of the bicyclic β-lactams are shown to be strongly dependent upon the pattern of substituents on the thiazolidinylacetic acid.The synthesis of cephams using homocysteamine is also described.
Synthesis of Biheteroaromatic Compounds via the Isoxazoline Route
Ghabrial, Sami S.,Thomsen, I.,Torssell, K. B. G.
, p. 426 - 434 (2007/10/02)
A number of heteroaromatically substituted furans, thiophenes, pyrroles, pyridines and benzenes have been prepared via the 2-isoxazoline route.N-Acetylnornicotyrine is prepared from N-allylacetamide and 3-pyridinecarboxaldoxime.
