Photochemical approach to functionalized benzobicyclo[3.2.1]octene structures via fused oxazoline derivatives from 4- and 5-(o-vinylstyryl)oxazoles

• Ivana Šagud,
• Simona Božić,
• Željko Marinić and
• Marija Šindler-Kulyk

Beilstein J. Org. Chem. 2014, 10, 2222–2229, doi:10.3762/bjoc.10.230

• framework of numerous important biologically active natural compounds or their metabolites [1]. Properly functionalized bicyclo[3.2.1]octanes have proved as useful reactive intermediates in stereoselective transformations making these derivatives powerful building blocks in organic synthetic strategies [2

Palladium-catalysed cyclisation of alkenols: Synthesis of oxaheterocycles as core intermediates of natural compounds

• Miroslav Palík,
• Jozef Kožíšek,
• Peter Koóš and
• Tibor Gracza

Beilstein J. Org. Chem. 2014, 10, 2077–2086, doi:10.3762/bjoc.10.216

Streptopyridines, volatile pyridine alkaloids produced by Streptomyces sp. FORM5

• Ulrike Groenhagen,
• Michael Maczka,
• Jeroen S. Dickschat and
• Stefan Schulz

Beilstein J. Org. Chem. 2014, 10, 1421–1432, doi:10.3762/bjoc.10.146

• -pyridinecarbaldehyde (19) a mixture of four diastereoisomers of 2-(1,3-pentadienyl)pyridine was formed (Figure 4), all showing similar mass spectra. These four diastereomers proved to be identical to the natural compounds 9 to 12 by comparison of mass spectra and GC retention. The major compound, 2-((1E,3E)-penta-1,3

Selective allylic hydroxylation of acyclic terpenoids by CYP154E1 from Thermobifida fusca YX

• Anna M. Bogazkaya,
• Clemens J. von Bühler,
• Sebastian Kriening,
• Alexandrine Busch,
• Alexander Seifert,
• Jürgen Pleiss,
• Sabine Laschat and
• Vlada B. Urlacher

Beilstein J. Org. Chem. 2014, 10, 1347–1353, doi:10.3762/bjoc.10.137

• products, mainly epoxides but also allylic alcohols [19]. Later a CYP102A1 double mutant F87V/A328L was identified producing 80% allylic alcohols starting with geranylacetone [20]. These hydroxylated products are useful building blocks for the total syntheses of several natural compounds including

Consecutive isocyanide-based multicomponent reactions: synthesis of cyclic pentadepsipeptoids

• Angélica de Fátima S. Barreto,
• Otilie E. Vercillo,
• Ludger A. Wessjohann and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2014, 10, 1017–1022, doi:10.3762/bjoc.10.101

• reactions; Passerini reaction; sansalvamide A; Ugi reaction; Introduction Peptoids are an interesting class of non-natural compounds that have recently received much attention due to their wide range of biological activities, which makes them attractive candidates for drug discovery [1][2][3][4][5][6][7

• ]. Depsipeptides are polymeric natural compounds, analogues of peptides, being formed by amino acids and hydroxy acids linked together by amide and ester bonds. These natural products show promising biological activities, especially regarding their therapeutic potential in cancer treatment [19]. An example of a

Addition of H-phosphonates to quinine-derived carbonyl compounds. An unexpected C9 phosphonate–phosphate rearrangement and tandem intramolecular piperidine elimination

• Łukasz Górecki,
• Artur Mucha and
• Paweł Kafarski

Beilstein J. Org. Chem. 2014, 10, 883–889, doi:10.3762/bjoc.10.85

• ; Introduction Medicinal, organocatalytic and stereoselective properties of quinine make it the most prominent representative of Cinchona alkaloids [1], a group of natural compounds of a unique three-dimensional structure. The structure involves a particular arrangement of two rigid heterocyclic fragments

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

• Sebastian Krüger and
• Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

• sexual pheromone of brown algae (20). Proposed biosynthesis of occidenol (25) and related natural compounds. Gaich’s bioinspired system using the DVCPR to mimick the dimethylallyltryptophan synthase. DMAPP = dimethylallyl pyrophosphate. Iguchi’s total synthesis of clavubicyclone, part 1. Iguchi’s total

Plakilactones G and H from a marine sponge. Stereochemical determination of highly flexible systems by quantitative NMR-derived interproton distances combined with quantum mechanical calculations of ¹³C chemical shifts

• Simone Di Micco,
• Angela Zampella,
• Maria Valeria D’Auria,
• Carmen Festa,
• Simona De Marino,
• Raffaele Riccio,
• Craig P. Butts and
• Giuseppe Bifulco

Beilstein J. Org. Chem. 2013, 9, 2940–2949, doi:10.3762/bjoc.9.331

• Software Package [27]) and taking into account the Boltzmann-weighted average derived from the energies of the single conformers. The analysis was carried out with linear regression analysis by using values as intercept and slope, which were obtained at the same level of theory for a set of known natural

• compounds [26]. Moreover, we considered the diagnostic carbons and calculated the difference with the experimental values that were re-acquired and reassigned in CDCl3 (Supporting Information File 1, Table S1), to avoid the introduction of explicit solvent molecules in the calculations, as required for a

Halogenated volatiles from the fungus Geniculosporium and the actinomycete Streptomyces chartreusis

• Tao Wang,
• Patrick Rabe,
• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2767–2777, doi:10.3762/bjoc.9.311

• the carrier gas was He at 1.2 mL min−1. The GC was programmed as follows: 5 min at 50 °C increasing with 5 °C min−1 to 320 °C. Retention indices (I) were determined from a homologous series of n-alkanes (C8–C38). The mass spectra of the natural compounds X and Y are shown in Figure 2. For comparison

Total synthesis of ochnaflavone

• Monica M. Ndoile and
• Fanie R. van Heerden

Beilstein J. Org. Chem. 2013, 9, 1346–1351, doi:10.3762/bjoc.9.152

• synthesis of 1 would be to start with the preparation of a diaryl ether. This functionality is present in many important bioactive natural compounds [19] and it is not surprising that a great amount of effort has been focused on the development and improvement of the methods to form diaryl ethers [20][21

Algicidal lactones from the marine Roseobacter clade bacterium Ruegeria pomeroyi

• Ramona Riclea,
• Julia Gleitzmann,
• Hilke Bruns,
• Corina Junker,
• Barbara Schulz and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2012, 8, 941–950, doi:10.3762/bjoc.8.106

• to those of the natural compounds revealed that the first-eluting minor diastereomer of 2-methylpentan-4-olide emitted by R. pomeroyi is the cis-diastereomer 7 and the main compound is the trans-diastereomer 8. Accordingly, the structures of the cis- and trans-diastereomers 9 and 10 were assigned to

Identification and isolation of insecticidal oxazoles from Pseudomonas spp.

• Florian Grundmann,
• Veronika Dill,
• Andrea Dowling,
• Aunchalee Thanwisai,
• Edna Bode,
• Narisara Chantratita,
• Richard ffrench-Constant and
• Helge B. Bode

Beilstein J. Org. Chem. 2012, 8, 749–752, doi:10.3762/bjoc.8.85

• nonnatural derivatives were synthesized to get a more diverse set of oxazole derivatives differing from the natural compounds by unusual (compound 9 and 10) or very long (compound 11) acyl chains. Additionally, the synthetic intermediates were also tested as precursors in labeling experiments as described

Carbamate derivatives and sesquiterpenoids from the South China Sea gorgonian Melitodes squamata

• Li-Si Huang,
• Fei He,
• Hui Huang,
• Xiao-Yong Zhang and
• Shu-Hua Qi

Beilstein J. Org. Chem. 2012, 8, 170–176, doi:10.3762/bjoc.8.18

• rarely found in marine natural compounds, and 7 showed moderate antibacterial activity. The possible biosynthesis routes of 1–5 were conjectured. Keywords: carbamate; gorgonian; Melitodes squamata; sesquiterpenoid; Introduction Gorgonians are recognized to mainly produce acetogenins, sesquiterpenoids

• NMR data comparison of the –CH2NHCH2CH2SO3H group in 6 with literature data [12][13]. The IR spectrum of 6 contains two strong bands at 1217 and 1041 cm−1, which supports the presence of a sulfonic acid group. The –NHCH2CH2SO3H group has rarely been found in marine natural compounds, such as N

The interplay of configuration and conformation in helical perylenequinones: Insights from chirality induction in liquid crystals and calculations

• Elisa Frezza,
• Silvia Pieraccini,
• Stefania Mazzini,
• Alberta Ferrarini and
• Gian Piero Spada

Beilstein J. Org. Chem. 2012, 8, 155–163, doi:10.3762/bjoc.8.16

• Bologna, Italy Dipartimento di Scienze Molecolari Agroalimentari, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy 10.3762/bjoc.8.16 Abstract The chirality transfer in liquid crystals induced by two helical perylenequinones (namely, the natural compounds cercosporin and phleichrome

The arene–alkene photocycloaddition

• Ursula Streit and
• Christian G. Bochet

Beilstein J. Org. Chem. 2011, 7, 525–542, doi:10.3762/bjoc.7.61

• numerous applications of meta photocycloaddition in total syntheses show that this reaction can be a very efficient tool to access polycyclic natural compounds. However, the cores directly obtained are usually not useful as such, and cleavage of the cyclopropyl ring must be carried out to access naturally

(Pseudo)amide-linked oligosaccharide mimetics: molecular recognition and supramolecular properties

• José L. Jiménez Blanco,
• Fernando Ortega-Caballero,
• Carmen Ortiz Mellet and
• José M. García Fernández

Beilstein J. Org. Chem. 2010, 6, No. 20, doi:10.3762/bjoc.6.20

• interest because these functional groups are isosteric with phosphodiesther groups occurring in oligoglycosylphosphates and nucleotides. Some examples of natural compounds having saccharide units connected by pseudoamide linkage are known. For example, the family of glycocinnamoylspermidine antibiotics 26

An enantiomerically pure siderophore type ligand for the diastereoselective 1 : 1 complexation of lanthanide(III) ions

• Markus Albrecht,
• Olga Osetska,
• Thomas Abel,
• Gebhard Haberhauer and
• Eva Ziegler

Beilstein J. Org. Chem. 2009, 5, No. 78, doi:10.3762/bjoc.5.78

• enterobactin (Figure 1) [6][7][8]. It has inspired the synthesis of a wide series of non-natural compounds which are used for metal ion binding and medical purposes [9][10][11][12][13][14][15][16][17][18][19][20][21][22]. However, the efficiency of this artificial chelators to bind iron(III) excels only in few

Ring strain and total syntheses of modified macrocycles of the isoplagiochin type

• Andreas Speicher,
• Timo Backes,
• Kerstin Hesidens and
• Jürgen Kolz

Beilstein J. Org. Chem. 2009, 5, No. 71, doi:10.3762/bjoc.5.71

• stereochemical correlation between isoplagiochin C (1) and isoplagiochin D (2) was also confirmed experimentally by hydrogenolysis of enantiopure samples of (PA)-1 to give and (PA)-2 (Scheme 1), and of (MA)-1 to give and (MA)-2, respectively, without any racemization [14]. The natural compounds isoplagiochin D

• protecting groups should be studied. Results and Discussion In our total syntheses of the racemic natural compounds 1 and 2 reported previously [15] the common and crucial precursor was the tetramethyl ether 3. Surprisingly and in contrast to the NMR results mentioned above for 1, closer NMR examination now

• mechanic and semi-empirical calculations for tetramethyl protected target compounds. Together with the molecules “in hand” they clearly demonstrated that the bridge between a–d should be saturated or at least a Z double bond as in the natural compounds 1 (cf. 3) and 2 (cf. 4). An E double bond or an alkyne

Stereoselective synthesis of (2S,3S,4Z)-4-fluoro- 1,3-dihydroxy- 2-(octadecanoylamino)octadec- 4-ene, [(Z)-4-fluoroceramide], and its phase behavior at the air/water interface

• Gergana S. Nikolova and
• Günter Haufe

Beilstein J. Org. Chem. 2008, 4, No. 12, doi:10.3762/bjoc.4.12

• -diol (4-fluoroceramide, 2b) having the D-erythro-configuration (2S,3S) and the trans-configured C(4)-C(5) double bond of the natural compounds 1a and 2a (Figure 1). Our first investigations on the phase behavior at the air/water interface of 4-fluoroceramide (2b) and its non-fluorinated analogue 2a by

8-epi-Salvinorin B: crystal structure and affinity at the κ opioid receptor

• Thomas A. Munro,
• Katharine K. Duncan,
• Richard J. Staples,
• Wei Xu,
• Lee-Yuan Liu-Chen,
• Cécile Béguin,
• William A. Carlezon Jr. and
• Bruce M. Cohen

Beilstein J. Org. Chem. 2007, 3, No. 1, doi:10.1186/1860-5397-3-1

• ] The epimers can be readily identified by TLC: the unnatural compounds almost invariably spot above the natural compounds in EtOAc/hexanes, and give a blue rather than pink/purple colour when visualized with vanillin.[19] The unnatural epimers are also recognizable by their distinctive H-12 multiplet

Colchitaxel, a coupled compound made from microtubule inhibitors colchicine and paclitaxel

• Karunananda Bombuwala,
• Thomas Kinstle,
• Vladimir Popik,
• Sonal O. Uppal,
• James B. Olesen,
• Jose Viña and
• Carol A. Heckman

Beilstein J. Org. Chem. 2006, 2, No. 13, doi:10.1186/1860-5397-2-13

• interest has been focused on new, highly-active classes of natural products such as the dolastatins and the cryptophycins. Such natural compounds and their synthetic derivatives have been evaluated for dosage and side effects in preliminary clinical trials [12][13][14][15], but the results do not suggest

Study of thioglycosylation in ionic liquids

• Jianguo Zhang and
• Arthur Ragauskas

Beilstein J. Org. Chem. 2006, 2, No. 12, doi:10.1186/1860-5397-2-12

• ionic liquids for the synthesis of alkyl glycoside and disaccharides via coupling of thioalkyl glycosyl donors with glycal acceptors. Alkyl glycosides and oligosaccharides are important intermediates and products in the synthesis of biologically active natural compounds and mimics. For example, tetra-O