Synthesis of Analogs of Natural Isoflavonoids Containing Phloroglucinol

Analogs of the natural isoflavonoids biochanin A and orobol were synthesized. Alkylation involving phenolic hydroxyls and the chromone ring was studied.     

Enantiospecific Synthesis of Trisubstituted Butyrolactone Natural Products and Their Analogs

A general methodology for the synthesis of highly substituted butyrolactones in enantiomerically pure form has been developed. The application of this process in a highly efficient synthesis of lactone natural products blastmycinone (1), NFX-2 (2), antimycinone (3), and NFX-4 (4) and two lipid metabolites (5, 6) are described. Additionally, the total synthesis of 5-epi-blastmycinone (22), 5-epi-NFX-2 (21b), 5-epi-NFX-4 (21c), and lipid metabolite analogs (19, 20) are also described. The overall yields for the target molecules are the highest reported so far in the literature.     

Studies on the Synthesis of a Natural Product—Piceatannol and its Analogs

Piceatannol,(E)-3,3′,4,5′-tetrahydroxy stilbene, a natural polyhydroxy stibene, possesses many biological activities, its synthesis has been reported. We designed another route of its synthesis, which can be controlled more easily. The synthetic product was characterized by elemental analysis,IR,MS and ^1H-NMR. Its analogs were synthesized by the similar method.     

Synthesis of Pseudobaptigenin Analogs

Homologs of the natural isoflavonoid pseudobaptigenin containing benzodioxane and benzodioxepane fragments were synthesized. Methanesulfonyl, carbamoyl, aminomethyl, and coumarin-containing isoflavone derivatives were prepared.     

Synthesis of Phenylalanine Analogs

A straightforward synthesis of phenylalanine analogs is described. Cerium ammonium nitrate (CAN) mediated addition of azide to cinnamic ester, followed by reaction with sodium acetate afforded the α‐azidocinnamate in moderate yield. Hydrogenation of α‐azidocinnamate, followed by BOC, CBZ or Fmoc protection gave phenylalanine analogs. A new approach for synthesizing racemic p‐boronophenylalanine analog was also explored.     

Synthesis of Formononetin Analogs

Derivatives of the natural isoflavone formononetin were synthesized. Acylation and alkylation of the phenolic hydroxyls and the chromone ring were investigated.     

Enzymatic Synthesis of Variediene Analogs

Five analogs of dimethylallyl diphosphate (DMAPP) with additional or shifted Me groups were converted with isopentenyl diphosphate (IPP) and the fungal variediene synthase from Aspergillus brasiliensis (AbVS). These enzymatic reactions resulted in the formation of several new terpene analogs that were isolated and structurally characterised by NMR spectroscopy. Several DMAPP analogs showed a changed reactivity giving access to compounds with unusual skeletons. Their formation is mechanistically rationalised and the absolute configurations of all obtained compounds were determined through a stereoselective deuteration strategy, revealing absolute configurations that are analogous to that of the natural enzyme product variediene.     

Synthesis of Cytotoxic Isodeoxypodophyllotoxin Analogs

A series of aryltetralin lignans 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i , 7j , 7k , 7l were synthesized as cytotoxic isodeoxypodophyllotoxin analogs. The title compounds 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i , 7j , 7k , 7l were synthesized from the reaction of (+)‐(R )‐4‐[benzo(d )(1,3)dioxol‐5‐ylmethyl]‐dihydrofuran‐2‐(3H )‐one with different arylaldehydes to afford benzyl alcohol analogs and subsequent cyclization with trifluoroacetic acid in dichromethane. The preliminary screening of the compounds against viability of blood cancer human cell line K562 revealed that compounds 7d , 7e , and 7f had higher inhibitory activity at 10 µg/mL concentration compared with etoposide as reference drug.     

One-Pot Synthesis of Phenytoin Analogs

A series of phenytoin analogs (5,5-diphenylimidazolidine-2,4-dione or 5,5-diphenyl-hydantoin) were synthesized in 65–75% yield from the corresponding substituted benzils. The same products were also obtained directly from -hydroxy ketones via one-pot procedure.     

氘代Rigosertib类似物的合成

以2,4,6-三羟基苯甲醛为原料制得中间体2,4,6-三甲氧基苯甲醛(2a)和2,4,6-三三氘甲氧基苯甲醛(2b);以4-烷氧基-3-硝基苄硫基乙酸为原料,经氧化、缩合-脱羧、还原、取代和水解5步反应合成了氘代Rigosertib类似物,收率80%~86%,其结构经1H NMR和MS表征。     

Cycloaddition of 1-Aryl-3-trimethylsiloxy-1,3-butadienes in the Synthesis of Natural Quinone Analogs

7-Hydroxy-5-(2-methoxyphenyl)-2-methyl-6-R-1,4-naphthoquinones, 8-hydroxy-1-(2-methoxyphenyl)-3-oxo-1,2,3,4-tetrahydro-9,10-anthraquinone, and 2-ethoxycarbonyl-8-hydroxy-1-(2-methoxyphenyl)-3-trimethylsiloxy-1,1a,4,4a-tetrahydro-9,10-anthraquinone were synthesized by reactions of 1-(2-methoxyphenyl)-2-R-3-trimethylsiloxy-1,3-butadienes with 2-bromo-5-methyl-1,4-benzoquinone and juglone. 1-Aryl-2-ethoxycarbonyl-3-trimethylsiloxy-1,3-butadienes reacted with 1,4-naphthoquinone to afford 1-aryl-2-ethoxycarbonyl-3-hydroxy-9,10-anthraquinones and their 4,4a-dihydro derivatives.     

Synthesis of New Phosphono Desmuramyldipeptide Analogs

Abstract

Muramyldipeptide (MDP) is the minimal bacterial cell wall moiety with imniunomodulating activity [I]. It is known that N-acetylglucosamine part is not essential lor immunomodulating activity and it can be replaced by phthalimido 01 adamantyl substituted side chains [2]. In our previous work we have modified the peptide backbone of phthaliniido-MDP analogs by introducing the phosphonamide 01 phosphinamide moiety at the end of the acyclic side chain or between Ala and Glu [3, 4]. We report the synthesis of phthalimido-MDP analog 2, where the o-carboxylic group of Glu is replaced by phosphonate moiety. Compound 1, which is orthogonally protected D,L-Abu(P), was prepared from benzyl 4-bromo-2-phthalimidobutyrate and triethyl phosphite. After removal of the phthalimide protecting group the obtained compound was coupled with Boc-L-Ah. Boc group was removed and the product was coupled with 5-phthalimidopentanoic acid to give 2. Both benzyl and ethyl protection can be selectively removed under mild conditions (catalytic hydrogenation. Nal).     

可交联嘌呤类脱氧核苷类似物的合成

可交联嘌呤类脱氧核苷是天然脱氧核苷类似物,可与互补链中配对碱基上的胺基发生链间交联反应,导致DNA双链发生不可逆转的交联,对开发核苷类药物和控制修饰基因表达等方面有重要应用。本文开发了一条新的合成路径,该方法以商业化的1-氯-2-脱氧-3,5-二-O-对甲苯甲酰基-D-呋喃核糖为起始原料,经由简便的合成路线制备了目标产...     

Synthesis of Nonracemic Tetrazole GABA Analogs

Russian Journal of Organic Chemistry - Nonracemic 3-substituted 4-(1H-tetrazol-1-yl)butanoic acids, analogs of the neurotropic drugs phenibut, tolibut, and baclofen, were synthesized by a...     

Synthesis of Galactosylhydroxylysine and its Analogs

Synthesis of (--)-galactosylhydroxylysine (GHL, I), and its analogs (+)-2 and (+)-3, which are essential for development of assays for osteoporosis, is described starting from (2S,5R)-(+)-hydroxylysine (4).     

前列环素(PGI2)及其类似物的合成

本文综述了前列环素及其类似物的合成。类似物包括有7-羰基—、10,10-二氟—、5-氯—,4-羰基—、6,9-硫—、6,9-氮—,6 a-碳—前列环素以及苯前列环素等。前列环素及其类似物是一类具有抑制血小板聚集的生物活性化合物。     

Synthesis and Stability of GNRA-Loop Analogs

Nebularine, 9-(β-D -ribofuranosyl)-9H-purin-2-amine, and inosine phosphoramidites 8 , 16 , and 17 , respectively, were synthesized and incorporated into the GNRA tetraloop at different positions (see Scheme, Table, and Fig. 4). The oligomers were investigated by means of UV and CD spectroscopy to address the question of how the individual base-modified N-nucleosides contribute to changes in H-bonding and base-stacking interactions within the loop. Several CD spectra are given and compared with each other (Figs. 5 and 6). The exchange of the loop sequence in position 4 and 7 results in a distinct change in base stacking. CD-Band shifting allows us to advance the hypothesis that a transition from a GNRA-type towards a UNCG-type base stacking is observed.     

Studies on the Synthesis of Pyridine Analogs of the Natural Product3,5,4''''-Trimethoxystilbene

3,5,4'-Trimethoxystilbene is the methoxy precursor of a natural product 3,5,4'-trihydro- xystilbene (resveratrol)1 , which was reported to have many biological activities2. 3,5,4'-trimethoxystilbene itself is also a natural product2. We have synthesized 3,5,4'-trimethoxystilbene. In the screening of its anti-tumor activity using three different human cancer cell lines, 3,5,4'-trimethoxystilbene was found to have an IC50 5.91 mol/L for KB, 5.82 mol/L for A2780, 7.08 mol/L for HCT-8, respe…     

Synthesis of Analogs of Anacardosidefrom Sem ecarpusAnacardium

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Efficient Synthesis of Thalifoline and Its Analogs

Thalifoline (1) and its analogs were synthesized from methyl 3-hydroxy-4-methoxy benzoate by prenyl etherification, Claisen rearrangement, oxidation, imine formation, reductive amination and intramolecular amidation. The last three steps, imine formation, reductive amination, and intramolecular amidation, were completed in one pot at room temperature.