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Viburspiran belongs to the class of maleidride natural products and it exhibits interesting biological properties such as antifungal activity. While no total synthesis of viburspiran has been reported, studies in our group are ongoing using a photochemical approach. This report focuses on asymmetric strategies applied to the current route to enable an enantioselective synthesis of viburspiran. The first approach made use of chiral auxiliaries, but this proved unsatisfactory. To overcome this problem, an organocatalytic reaction was investigated, giving better results. Having obtained aldehyde 10 via an asymmetric conjugate addition using the chiral proline-derived catalyst (S)-9, Pinnick oxidation followed by Fisher esterification, intramolecular Claisen condensation and iPrOH protection finally afforded the six-membered enol ether 11 with an enantiomeric excess of approximately 89%, successfully completing an asymmetric route to this key intermediate.

Alcohol dehydrogenases (ADHs) have become important catalysts for stereoselective oxidation and reduction reactions of alcohols, aldehydes and ketones. The aim of this contribution is to provide the reader with a timely update on the state-of-the-art of ADH-catalysis. Mechanistic basics are presented together with practical information about the use of ADHs. Current concepts of ADH engineering and ADH reactions are critically discussed. Finally, this contribution highlights some prominent examples and future-pointing concepts., BT/Biocatalysis

A new approach for the synthesis of 9-membered N,N,O-heterocycles by Pd-catalyzed [6+3] dipolar cycloaddition of N-iminoisoquinolinium ylides and 2-vinyl oxetanes has been developed. The scope of this cycloaddition was demonstrated with 28 examples. This is another important synthetic strategy for medium-sized rings by employing N-iminoisoquinolinium ylides as ternary synthons.

Planar chiral monodentate 1,3-disubstituted ferrocene phosphines inspired on JohnPhos-type ligands have been synthesized and applied to the enantioselective gold(I) catalyzed [4 + 2] cycloaddition of 1,6-arylenynes. Computational studies rationalized the working mode of the catalyst on the folding of the substrate in the chiral environment of the ligand involving attractive noncovalent interactions.

Spontaneous deracemizations is a challenging, multidisciplinary subject in current chirality research. In the absence of any chiral inductors, an achiral substance or a racemic composition is driven into an enantioenriched or even homochiral state through a selective energy input, e.g., chemical potential, photoirradiation, mechanical grinding, ultrasound waves, thermal gradients, etc. The most prominent examples of such transformations are the Soai reaction and the Viedma deracemization. In this review, we track the most recent developments in this topic and recall that many other deracemizations have been reported for solutions from mesophases to conglomerate crystallizations. A compiled set of simply available achiral organic, inorganic, organometallic, and MOF compounds, yielding conglomerate crystals, should give the impetus to realize new experiments on spontaneous deracemizations. Taking into account thermodynamic constraints, modeling efforts have shown that structural features alone are not sufficient to describe spontaneous deracemizations. As a guideline of this review, particular attention is paid to the physicochemical origin and symmetry requirements of such processes.

Gastric cancer is one of the deadliest cancers in modern societies, so there is a high level of interest in discovering new drugs for this malignancy. Previously, we demonstrated the ability of tryptophanol-derived polycyclic compounds to activate the tumor suppressor protein p53, a relevant therapeutic target in cancer. In this work, we developed a novel series of enantiomerically pure tryptophanol-derived small molecules to target human gastric adenocarcinoma (AGS) cells. From an initial screening of fourteen compounds in AGS cell line, a hit compound was selected for optimization, leading to two derivatives selective for AGS gastric cells over other types of cancer cells (MDA-MB-231, A-549, DU-145, and MG-63). More importantly, the compounds were non-toxic in normal cells (HEK 293T). Additionally, we show that the growth inhibition of AGS cells induced by these compounds is mediated by apoptosis. Stability studies in human plasma and human liver microsomes indicate that the compounds are stable, and that the major metabolic transformations of these molecules are mono- and di-hydroxylation of the indole ring.

The ability of highly energetic metal-carbene intermediates to engage in complex cascade or formal cycloaddition processes is one of the most powerful tools for building intricate molecular architectures in a straightforward manner. Among this type of organometallic intermediates, non-acceptor metal carbenes are particularly challenging to access and, therefore, have experienced slower development. In this regard, our group has exploited the use of electrophilic gold(I) complexes to selectively activate certain classes of substrates for the generation of this type of intermediate. Thus, very different types of molecules, such as enynes or 7-substituted cycloheptatrienes, lead to the formation of carbenes under gold(I) catalysis. Related rhodium(II) carbenes can also be generated from cycloheptatrienes. In this account, we aim to summarize our efforts towards the in situ generation of such highly versatile organometallic species as well as studies on their reactivity through formal cycloadditions or complex cascade reactions.

Gold(I) catalysts are ideal for the activation of alkynes under very mild conditions. However, unlike allenes or alkenes, the triple bond of alkynes cannot be prochiral. In addition, the linear coordination displayed by gold(I) complexes places the chiral ligand far away from the substrate resulting in an inefficient transfer of chiral information. This poses a significant challenge for the achievement of high enantiocontrol in gold(I)-catalyzed reactions of alkynes. Although considerable progress on enantioselective gold(I)-catalyzed transformations has recently been achieved, the asymmetric activation of non-prochiral alkyne-containing small molecules still represents a great challenge. Herein we summarize recent advances in intra- and intermolecular enantioselective gold(I)-catalyzed reactions involving alkynes, discussing new chiral ligand designs that lie at the basis of these developments. We also focus on the mode of action of these catalysts, their possible limitations towards a next-generation of more efficient ligand designs. Finally, square planar chiral gold(III) complexes, which offer an alternative to chiral gold(I) complexes, are also discussed.

This review provides an extensive summary of the effects of carbohydrate fluorination with regard to changes in physical, chemical and biological properties with respect to regular saccharides. The specific structural, conformational, stability, reactivity and interaction features of fluorinated sugars are described, as well as their applications as probes and in chemical biology.

The Moroccan locust, Dociostaurus maroccanus (Thunberg, 1815) (Orthoptera: Acrididae), is a polyphagous pest capable of inflicting large losses in agriculture under favorable environmental and climatic conditions. Currently, control of the pest relies solely on the application of conventional insecticides that have negative effects on the environment and human safety. In the search for a more rational, environmentally acceptable approach for locust control, we have previously reported that (Z/E)-phytal (1) is a male-produced candidate sex pheromone of this acridid. This molecule, with two stereogenic centers at C-7 and C-11, has four different diastereomers along with the Z/E stereochemistry of the double bond at C-2. In this paper, we present for the first time the enantioselective synthesis of the four diastereomers of (E)-phytal and their electrophysiological and behavioral activity on males and females. Our results demonstrate that the (R,R)-phytal is the most active diastereomer in both assays, significantly attracting females in a double-choice Y olfactometer, and confirming the previous chromatographic assignment as component of the sex pheromone of the Moroccan locust. © 2018 American Chemical Society.

Ispitana je dvostruka asimetrična indukcija u aldolnim reakcijama između dioksanona i hiralnih acikličnih α-supstituisanih aldehida katalizovanih prolinom, i tom prilikom je utvrđeno da je stereohemijski ishod ove reakcije kontrolisan reagensom, sa dobrim stepenom dijastereoselektivnosti. Sa cikličnim aldehidima stereokontrola nije zadovoljavajuća. Takođe, kombinacijom organokatalizovane aldolizacije i reduktivnog aminovanja, sintetisano je šest biološki aktivnih jedinjenja: (+)-2-epi-hiacintacin A2, (–)-3-epihiacintacin A1, 1-deoksi-galaktonodžirimicin (DGJ), 2,5-dideoksi-2,5-imino-D-altritol (DIA), (–)-4-epi-fagomin i (+)-aza-galaktofagomin. Pored ovih iminošećera, istim pristupom sintetisano je još tri molekula - pipekolinska kiselina, 3-hidroksipipekolinska kiselina i 4-deoksifagomin - koji predstavljaju sintetički značajne intermedijere za dobijanje drugih biološki aktivnih jedinjenja. U svim sintezama kao ključna reakcija korišćena je asimetrična aldolna adicija 2,2-dimetil-1,3-dioksan-5-ona (dioksanona) na odgovarajući aldehid katalizovana prolinom i praćena reduktivnim aminovanjem. Formirana su dva nova stereocentra primenom principa katalitičke asimetrične sinteze i jedan dijastereoselektivnim reduktivnim aminovanjem., Double asymmetric induction was investigated in proline-catalyzed aldol additions between dioxanone and chiral α-substituted aldehydes, and it was found that, with acyclic aldehydes, the stereochemical outcome of this reaction was controlled by a reagent, with a good level of diastereoselectivity. Stereocontrol with cyclic aldehydes is not satisfactory. Six biologically active compounds as well as some significantly useful intermediates were synthesized by a combination of organocatalytic aldol addition and reductive amination: (+)-2-epi-hyacinthacine A2, (–)-3-epi-hyacinthacine A1, 1-deoxygalactonojirimycin (DGJ), 2,5-dideoxy-2,5-imino-D-altritol (DIA), (–)-4-epi-fagomine and (+)- aza-galacto-fagomine. In addition to these iminosugars, three other molecules - pipecolic acid, 3-hydroxypipecolic acid and 4-deoxyfagomine - are synthesized by applying this tactical combination on the same way, and they are significant intermediates in synthesis of other biologically active compounds. Proline-catalyzed asymmetric aldol addition of 2,2-dimethyl-1,3-dioxan-5-one (dioxanone) to the corresponding aldehyde, followed by reductive amination, was used as the key transformation in all syntheses. Two new stereocentres were formed in these reactions using the principle of catalytic asymmetric synthesis and one by diastereoselective reductive amination.

The (3+2) cycloaddition between azomethine ylides and alkenes is an efficient, convergent and stereocontrolled method for the synthesis of unnatural pyrrolidine and proline scaffolds. In this review, the application of this reaction to the synthesis of enantiopure organometallic ligands for asymmetric catalysis is presented first. These new EhuPhos ligands can participate in a second generation of 1,3-dipolar reactions that generate an offspring of unnatural proline derivatives that behave as efficient organocatalysts. These densely substituted unnatural l-proline derivatives exhibit distinct features, different to those described for natural l-proline and its derivatives. Finally, several examples of biologically active proline derivatives obtained by means of (3+2) cycloadditions involving azomethine ylides are presented. These applications show the character of privileged structures of these polysubstituted pyrrolidine rings.

Byly připraveny katalyzátory odvozené od (2R,5S)-5-isopropyl-5-methyl-2-(pyridin- 2-yl)imidazolin-4-onu a 4-thionu a bazického uhličitanu měďnatého. Jejich katalytická aktivita byla testována při enantioselektivní Henryho reakci čtyř aromatických aldehydů s nitromethanem. Bylo zjištěno, že jejich katalytická aktivita je nižší v porovnání s homogenním katalyzátorem obdobného typu i s heterogenním katalyzátorem obsahujícím jako inertní nosič kopolymer PEG-polyglutamovou kyselinu. Nicméně mnohem snadnější příprava a manipulace s připravenými katalyzátory umožňuje jejich recyklaci. Srovnáním katalytické aktivity kyslíkatého a sirného katalyzátoru byla potvrzena vyšší aktivita prvně jmenovaného., Two catalysts based on (2R,5S)-5-isopropyl-5-methyl-2-(pyridin-2-yl) imidazolin-4- one and 4-thione with copper (II) carbonate have been prepared. Their catalytic activities have been tested in enatiosective Henry reaction of four aromatic aldehydes with nitromethane. It has been found that their catalytic activity is lower in comparison with both homogeneous as well as heterogeneous catalyst of similar type containing PEG-polyglutamic acid copolymer as inert matrix. However, much easier preparation and manipulation with prepared catalysts allow possibility of their recycling. The higher activity of oxygen catalyst has been found when compared to the catalytic activity of sulphur counterpart., Fakulta chemicko-technologická, Student~přednesl~cca 15 min. přednášku na téma své diplomové práce s~ názvem Heterogenní enantioselektivní katalyzátory založené na komplexu 5-isopropyl-5-methyl-2-(pyridin-2-yl)imidazolin-4-onu a 4-thionu s uhličitanem měďnatým. Poté byly přečteny posudky školitele a oponentky a diplomant se vyjádřil k dotazům oponentky. K obhajobě práce byly vzneseny následující dotazy. prof. Ing. Miloš Sedlák,~DrSc. Jaký jste používal uhličitan? prof. Ing. Filip Bureš,~Ph.D. Jak vypadá uhličitan, který používáte, jaká je jeho struktura? Zjišťoval jste skutečnou strukturu? doc. Ing.Radek Cibulka,~Ph.D. Jaké metody jste používal při charakterizaci katalyzátorů? Na všechny vznesené dotazy a připomínky diplomant~odpověděl~k plné spokojenosti členů komise.

A catalytic asymmetric synthesis of (+)-aza-galacto-fagomine (AGF) - the most promising compound for the pharmacological chaperone therapy of Krabbe disease was accomplished in six steps, in 14% overall yield. The synthesis hinges on the combination of organocatalyzed aldolization and reductive hydrazination.

The first and asymmetric total synthesis of (‒)-hedycoropyrans A (1) was accomplished in 18 steps with 5.4% overall yield. The key features of our strategy include 1) construction of the unusual trans-2-aryl-6-alkyl tetrahydropyran core via Achmatowicz rearrangement, Zn-mediated reductive deoxygenation and Heck-Matsuda coupling reaction, and 2) installation of 3,4-anti-dihydroxy from the corresponding 3,4-syn-dihydroxy THP through chemo- and regioselective IBX oxidation and Evans-Saksena reduction. In addition, C2 epimerization of (-)-hedycoropyan A (1) under the acidic condition furnished (‒)-Hedycoropyan B (2) with 71% yield. This finding might suggest the biogenetic origin of hedycoropyran B.

Acyclic nucleosides phosphonates have been prepared in a straightforward manner and in high yields by an enantioselective palladium-catalyzed allylic substitution involving nucleic bases as nucleophiles followed by cross-metathesis reaction with diethyl allylphosphonate.

A straightforward and atom-economical enantioselective approach to highly substituted tetrahydropyrans is reported. The process, which consists of an intermolecular gold-catalyzed [2+2+2] cycloaddition between allenamides, alkenes, and aldehydes, is efficiently catalyzed by both phosphoramidite- and chiral N-heterocyclic carbene-gold catalysts, occurs with complete chemoselectivity and regioselectivity, moderate diastereoselectivity, and moderate to very good enantioselectivities

New pyrrolidine-based organocatalysts with a bulky substituent at C2 were synthesized from chiral imines derived from (R)-glyceraldehyde acetonide by diastereoselective allylation followed by a sequential hydrozirconation/iodination reaction. The new compounds were found to be effective organocatalysts for the Michael addition of aldehydes to nitroolefins and enantioselectivities up to 85% ee were achieved.

A straightforward and atom-economical enantioselective approach to highly substituted tetrahydropyrans is reported. The process, which consists of an intermolecular gold-catalyzed [2+2+2] cycloaddition between allenamides, alkenes, and aldehydes, is efficiently catalyzed by both phosphoramidite- and chiral N-heterocyclic carbene-gold catalysts, occurs with complete chemoselectivity and regioselectivity, moderate diastereoselectivity, and moderate to very good enantioselectivities.

Acyclic nucleoside phosphonates have been prepared in a straightforward manner and in high yields by an enantioselective palladium-catalyzed allylic substitution involving nucleic bases as nucleophiles followed by cross-metathesis reaction with diethyl allylphosphonate.

This paper describes the enantioselective synthesis of analogues of sapinofuranones a and B, namely 5-substitutes dihydro- and 5H-furan-ones, and their in vitro growth inhibitory activity against six cancer cell lines in comparison with fungal furanones such as diplofuranone A, diplobifuranylones a and B, as well as (S, S)-enantiomer of sapinofuranone B. The compounds under study displayed weak if any in vitro growth inhibitory activity against the analysed cancer cell lines. However, it seems that among dihydro- and 5H-furan-ones bearing a 1-hydroxypentyl side chain, the stereochemistry of the furanone ring and that of hydroxylated methine could modify the in vitro growth activity of these compounds. The natural furanones that showed a different unsaturated chain at C-4 or rearranged into a dihydrofuran ring appeared to be inactive in terms of growth inhibitory activity, e.g. displaying growth inhibitory concentration at 50% (GI50) > 100 μM in all six cancer cell lines analysed., SCOPUS: ar.j, info:eu-repo/semantics/published

The gold-catalyzed enantioselective hydroazidation and hydroamination reactions of allenes are presented herein. ADC gold(I) catalysts derived from BINAM were critical for achieving high levels of enantioselectivity in both transformations. The sense of enantioinduction is reversed for the two different nucleophiles, allowing access to both enantiomers of the corresponding allylic amines using the same catalyst enantiomer.

Gold(I) complexes with N-acyclic aminocarbenes possess unique properties that make them potentially valuable for catalysis. These include high donor ability, conformational flexibility, and wide N−C(carbene)−N angles that can place bulky or chiral substituents near catalytic substrate binding sites. These derivatives are easily accessible through the reaction between gold isocyanide compounds with different amines. Complexes of the types 1 and 2 were prepared by the reaction between [AuCl(CNR)] and trans-2-diaminecyclohexane in the racemic or enantiomeric pure form, or N-((1R,2R)-2-aminocyclohexyl)-4-methylbenzenesulfonamide. (Scheme 1). The catalytic activity of species 1 and 2 has been tested in different multicomponent reactions. The reaction of aldehydes, amines and alkynes (A3-coupling) can lead, depending on the aldehyde, to the synthesis of indolicines or propargylamines (Scheme 2). Both are important scaffolds in the preparation of biologically active molecules, as the anticancer indolicine derivative “camptothecin”, or the MAO type inhibitors, with propargylamine moieties, used in the treatment of Parkinson’s disease. All the catalysts show excellent results in the preparation of several substituted indolicines or propargylamines under solvent free conditions, with yields until 99% with 1% mol catalyst. The chiral catalyst 1c and 2 were tested in the enantioselective synthesis of propargylamines with interesting results.

We report the synthesis and biological evaluation of a series of (-)-englerinA analogues obtained along our previously reported synthetic route based on a stereoselective gold(I) cycloaddition process. This synthetic route is a convenient platform to access analogues with broad structural diversity and has led us to the discovery of unprecedented and easier-to-synthesize derivatives with an unsaturation in the cyclopentyl ring between C4 and C5. We also introduce novel analogues in which the original isopropyl motif has been substituted with cyclohexyl, phenyl, and cyclopropyl moieties. The high selectivity and growth-inhibitory activity shown by these new derivatives in renal cancer cell lines opens new ways toward the final goal of finding effective drugs for the treatment of renal cell carcinoma (RCC).

Porous organic polymers have prospects as functional substrates for catalysis, with quite different molecular properties from inorganic substrates. Here we disclose for the first time that porous palladium(II)-polyimines are excellent catalysts for cooperatively catalyzed and enantioselective cascade reactions. In synergy with a chiral amine co-catalyst, polysubstituted cyclopentenes and spirocyclic oxindoles, including the all-carbon quaternary stereocenter, were synthesized in high yields. High diastereo- and enantioselectivities were achieved for these dynamic kinetic asymmetric transformations (DYKAT) of enals with propargylic nucleophiles.

A gold(I)-catalyzed enantioselective desymmetrization of 1,3-diols was achieved by intramolecular hydroalkoxylation of allenes. The catalyst system 3-F-dppe(AuCl)2/(R)-C8-TRIPAg proved to be specifically efficient to promote the desymmetrizing cyclization of 2-aryl-1,3-diols, which have proven challenging substrates in previous reports. Multisubstituted tetrahydrofurans were prepared in good yield with good enantioselectivity and diastereoselectivity by this method.

The enantioselective borylative dearomatization of a heteroaromatic compound has been achieved using a copper(I) catalyst and a diboron reagent. This reaction involves the regio- and enantioselective addition of active borylcopper(I) species to indole-2-carboxylates, followed by the diastereoselective protonation of the resulting copper(I) enolate to give the corresponding chiral indolines, which bear consecutive stereogenic centers.

Molybdenum-, tungsten-, and ruthenium-based complexes that control the stereochemical outcome of olefin metathesis reactions have been recently introduced. However, the complementary nature of these systems through their combined use in multistep complex molecule synthesis has not been illustrated. A concise diastereo- and enantioselective route that furnishes the anti-proliferative natural product neopeltolide is now disclosed. Catalytic transformations are employed to address every stereochemical issue. Among the featured processes are an enantioselective ring-opening/cross-metathesis promoted by a Mo monoaryloxide pyrrolide (MAP) complex and a macrocyclic ring-closing metathesis that affords a trisubstituted alkene and is catalyzed by a Mo bis(aryloxide) species. Furthermore, Z-selective cross-metathesis reactions, facilitated by Mo and Ru complexes, have been employed in the stereoselective synthesis of the acyclic dienyl moiety of the target molecule.

(NHC)copper(I) hydride catalyzed ketone hydrosilylation is an efficient method for the enantioselective synthesis of secondary alcohols. Herein, we represent a computational study of this reaction using density functional theory (DFT) on realistic model systems. This study is supported by kinetic investigations, using in situ FTIR measurements. The calculations validate the previously proposed reaction mechanism and explain the high activity of (OR 1)xR2 3-xSi-H types of silanes. Experimental evidence in favor of the monomeric (NHC)CuH form of the catalyst is also given. Combining experimental and theoretical results furthermore highlights a Lewis base activation of the hydrosilane, leading to a modified suggestion for the mechanistic scheme of the catalytic cycle. © 2014 American Chemical Society.

Some species of nudibranchs (Mollusca) protect themselves from predatory attacks by storing defensive terpene chemicals acquired from dietary sponges (Porifera) in specialized body parts called MDFs (mantle dermal formations), often advertising their unpalatability to potential predators by means of bright coloration patterns. Consequently, the survival of these trophic specialist species is closely related to the possibility of obtaining the defensive tools from sponges that live in their immediate vicinity; therefore, it is important to determine as precisely as possible the chemical composition of nudibranch extracts prior to any ecological studies addressing issues that involve their alimentary behavior and their defensive strategies, including the significance of their color patterns. Some of our recent studies on the chemical composition of terpene extracts from nudibranchs belonging to the genera Chromodoris and Hypselodoris are summarized. We also report the development of a method to assay extracts and purified metabolites for their feeding deterrent activity against co-occurring generalist predators. In a recent chemoecological study, showing that repugnant terpene chemicals are accumulated at extremely high concentrations in exposed parts of the nudibranchs' bodies, the feeding deterrence assays were carried out on the generalist marine shrimp Palaemon elegans, very common in the Mediterranean. We have modified this assay for use with the Australian shrimp species P. serenus, and confirmed the ecological validity of the assay by analysis of extracts from species of sponges and mollusks that live in the same habitat as P. serenus. The deterrent properties of haliclonacyclamine alkaloids isolated from the sponge Haliclona sp. were demonstrated, with the alkaloid mixture demonstrating palatability deterrence at concentrations as low as 0.05 mg/mL, and complete deterrence at 0.75 mg/mL. In contrast, the diterpene thuridillin metabolites from the sacoglossan m

The addition of a Grignard reagent to both enantiomeric N-tert-butanesulfinyl imines derived from 3-(2-bromophenyl)propanal 8 proceeded with high diastereoselectivity. The resulting sulfinamides 9 and 12 were easily transformed into tetrahydroquinoline alkaloids (-)-angustureine (4) and (-)-cuspareine (5) after three steps: N-desulfinylation, intramolecular N-arylation and N-methylation.

This review deals with stereoselective issues in PPAR ligands some of which are in clinical use for treating certain metabolic disorders. After a short introduction of these nuclear receptor and their agonists, some cases of enantiose-lective separations are reported. The main part concerns stereoselective synthesis first starting with asymmetric synthesis from chiral precursors followed by what we refer to as >true> enantioselective methods. Some examples are discussed in detail for each particular heading.

The anti-HIV nucleoside lamivudine was asymmetrically synthesized in only three steps via a novel surfactant-treated subtilisin Carlsberg-catalyzed dynamic kinetic resolution protocol. The enantiomer of lamivudine could also be accessed using the same protocol catalyzed by Candida antarctica lipase B., QC 20131108

An efficient one-pot synthesis of optically active beta-alkyl-substituted alcohols through a tandem copper-catalyzed asymmetric allylic alkylation (AAA) with organolithium reagents and reductive ozonolysis is presented. Furthermore, hydroboration-oxidation following the Cu-catalyzed AAA leads to the corresponding homochiral gamma-alkyl-substituted alcohols.

An efficient enantioselective synthesis of lactones was developed based on the catalytic asymmetric conjugate addition (ACA) of alkyl Grignard reagents to pyranones. The use of 2H-pyran-2-one for the first time in the ACA with Grignard reagents allows for a variety of further transformations to access highly versatile building blocks such as beta-alkyl substituted aldehydes or beta-bromo-gamma-alkyl substituted alcohols with excellent regio- and stereoselectivity.

Byla provedena literární rešerše týkající se posouzení biologických aktivit obou optických izomerů ibuprofenu tj. (2R)- a (2S)-2-(4-isobutylfenyl)propanové kyseliny. Byly diskutovány a zhodnoceny možnosti syntézy obou opticky čistých forem s využitím 2-(4-isobutylfenyl)propanové kyseliny. Byly diskutovány v literatuře popsané možné metody přípravy 2-(4-isobutylfenyl)propenové kyseliny. V experimentální části práce byla ověřena syntéza 2-(4-isobutylfenyl)propenové kyseliny a odpovídajícího methylesteru jako možných prekurzorů pro syntézu (2R)- a (2S)-2-(4-isobutylfenyl)propanové kyseliny., This bachelor work summarizes the biological activities assessment of both optical isomers of ibuprofen i.e. (2R)- and (2S)-2-(4-isobutylphenyl)propanoic acid. The possibilities of synthesis of both mentioned optically pure forms using 2-(4-isobutyl-phenyl)propanoic acid were discussed and evaluated. Several methods of preparation 2-(4-isobutylphenyl)-propenoic acid described in literature were discussed. Synthesis of 2-(4-isobutylphenyl)-propenoic acid and corresponding methyl ester as possible precursors for synthesis (2R)- and (2S)-2-(4-isobutylphenyl)propanoic acid was verified in the experimental part of the work., Ústav organické chemie a technologie, Student prezentoval svoji bakalářskou práci a vyjádřil se k připomínkám v posudku.