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

• ] and sydnones [11][12][13], as routes to polycyclic compounds, we turned our attention to oxazole derivatives. The oxazole structure is commonly found in natural products and pharmaceuticals [14][15][16][17] and is applied in useful reagents and intermediates in organic synthesis [18][19][20][21][22

• spectra in C6D6 of rel-(9S)-12a (a) and rel-(9S)-11 (b). Synthesis of 4- (1) and 5-(2-vinylstyryl)oxazoles (2). Irradiation of 4- (1) and 5-(2-vinylstyryl)oxazoles (2) (crude reaction mixtures). Plausible mechanisms of oxazoline ring-opening in photoproduct 10. Mechanism of the formation of polycyclic

• compounds (8–10). Reactions of the photochemical product 8 with EtOH, MeOD and H2O/silica gel. Plausible mechanisms of oxazoline ring opening in photoproduct 10 and formation of 12. Supporting Information Supporting Information File 560: Experimental part, NMR and IR spectra. Acknowledgements This work

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

Photochemical and thermal intramolecular 1,3-dipolar cycloaddition reactions of new o-stilbene-methylene-3-sydnones and their synthesis

• Kristina Butković,
• Željko Marinić,
• Krešimir Molčanov,
• Biserka Kojić-Prodić and
• Marija Šindler-Kulyk

Beilstein J. Org. Chem. 2011, 7, 1663–1670, doi:10.3762/bjoc.7.196

• such a system, where two chromophores, stilbene and sydnone, are divided by a methylene bridge, an intramolecular 1,3-dipolar cycloaddition and the formation of diverse polycyclic compounds could be expected. Herein we describe, for the first time, the synthesis of cis- and trans-3-(stilbenylmethyl

• cis or trans double bond of stilbene moiety, affording polycyclic compounds 11 and 12, respectively. The same starting compounds also react thermally: The sydnone moiety in 3a reacts as a masked azomethine dipole with trans configuration on the stilbene moiety by intramolecular [3 + 2] cycloaddition

Tribenzotriquinacenes bearing three peripheral or bridgehead urea groups stretched into the 3-D space

• Jörg Tellenbröker and
• Dietmar Kuck

Beilstein J. Org. Chem. 2011, 7, 329–337, doi:10.3762/bjoc.7.43

• bridgeheads of the rigid, convex–concave, C3v-symmetrical molecular framework are reported. 1H NMR data point to supramolecular aggregation of these TBTQ derivatives in low-polarity solvents. Keywords: convex–concave structures; polycyclic compounds; supramolecular chemistry; tribenzotriquinacenes; urea

Enantioselective synthesis of tricyclic amino acid derivatives based on a rigid 4-azatricyclo[5.2.1.0^2,6]decane skeleton

• Matthias Breuning,
• Tobias Häuser,
• Christian Mehler,
• Christian Däschlein,
• Carsten Strohmann,
• Andreas Oechsner and
• Holger Braunschweig

Beilstein J. Org. Chem. 2009, 5, No. 81, doi:10.3762/bjoc.5.81

• β-turn-inducing building blocks in peptidomimetics and for chiral auxiliaries in asymmetric organocatalysis. Keywords: amino acid; enantioselective synthesis; norbornane; polycyclic compounds; pyrrolidine; Introduction Unnatural amino acids with a rigid bowl-shaped backbone have received

Synthesis and Diels–Alder cycloaddition reaction of norbornadiene and benzonorbornadiene dimers

• Bilal Nişancı,
• Erdin Dalkılıç,
• Murat Güney and
• Arif Daştan

Beilstein J. Org. Chem. 2009, 5, No. 39, doi:10.3762/bjoc.5.39

• orientation) also confirms the exo structures for 11, 12, 18 and 19 (Figure 1). In summary, the synthesis and cycloaddition reaction of norbornadiene and benzonorbornadiene dimers was investigated and new norbornanoid polycyclic compounds, which open up several synthetic and mechanical investigations, were

New modification of the Perkow reaction: halocarboxylate anions as leaving groups in 3-acyloxyquinoline- 2,4(1H,3H)-dione compounds

• Oldřich Paleta,
• Karel Pomeisl,
• Stanislav Kafka,
• Antonín Klásek and
• Vladislav Kubelka

Beilstein J. Org. Chem. 2005, 1, No. 17, doi:10.1186/1860-5397-1-17

• , amides or acyl halides. [5][6] Examples of the successful Perkow reaction also include chlorofluoro ketones, e.g. 1,3-dichloro-1,1,3,3-tetrafluoroacetone,[7] α-halonitroalkanes, and in rare cases also polycyclic compounds[8] such as 3,3-dichloro-1-methylquinoline-2,4(1H,3H)-dione. [9] In the Perkow