Pyrrolizidine alkaloid derivatives are present in the androconial (male scent) organs of Prittwitzia hymenaea, Mechanitis isthmia veritabilis, Tithorea harmónia fúria (Lep., Ithomiinae), Amauris echeria and Euploea sylvester (Lep., Danainae). While the ithomiines contain the new pyrrolizidine alkaloid derivative methyl hydroxydanaidoate, the danaines contain the known derivatives danaidone and ...

A flexible method for the diastereoselective total synthesis of the pyrrolizidine alkaloids uniflorine A, casuarine, australine, and 3-epi-australine and the unnatural epimer 3,7-di-epi-australine from a common chiral 2,5-dihydropyrrole precursor is described.

The compounds [3-(2-Bromocyclohex-2-enyloxy)prop-1-ynyl]-tert-butyl-dimethylsilane 3, [4-(2-bromocyclohex-2-en-1-yloxy)but-2-yn-1-yloxy]tert-butyldimethylsilane 5 and dimethyl 2-(2-bromocyclohex-2-enyl)-2-(3-(tert-butyldimethylsilanyl)prop-2-ynyl)malonate 9 were prepared and subjected to palladium-catalyzed intra-intermolecular cascade cross couplings incorporating bicyclopropylidene 10 under t...

Polycyclic aromatic hydrocarbon growth from cyclopentadiene (CPD) pyrolysis was investigated using a laminar flow reactor operating in a temperature range of 600 to 950°C. Major products from CPD pyrolysis are benzene, indene and naphthalene. Formation of observed products from CPD is explained as follows. Addition of the cyclopentadienyl radical to a CPD π-bond produces a resonance-stabilized ...

The synthesis of the first multivalent pyrrolizidine iminosugars is reported. The key azido intermediates 4 and 31 were prepared after suitable synthetic elaboration of the cycloadduct obtained from 1,3-dipolar cycloaddition of D-arabinose derived nitrone to dimethylacrylamide. The key step of the strategy was the stereoselective installation of an azido moiety at C-6 of the pyrrolizidine skele...

3D-pharmacophore and 2D-QSAR modeling studies describe the anti-oncological properties of spiro-alkaloids. The dispiro[2H-indene-2,3'-pyrrolidine-2',3''-[3H]indole]-1,2''(1''H, 3H)-diones 20-38 were prepared via 1,3-dipolar cycloaddition reactions of azomethine ylides (generated in situ via decarboxylative condensation of isatins 7-9 with sarcosine 10) and 2-(arylmethylidene)-2,3-dihydro-1H-ind...

Seventeen pyrrolizidine alkaloids were studied with the hepatocyte primary culture-DNA repair test using rat hepatocytes. DNA repair synthesis was elicited by 15 alkaloids, including 11 of unknown carcinogenicity, i.e., senecionine, seneciphylline, jacobine, epoxyseneciphylline, senecicannabine, acetylfukinotoxin, syneilesine, dihydroclivorine, ligularidine, neoligularidine, and ligularizine. T...

THE TITLE COMPOUND, [SYSTEMATIC NAME: 5a-acet-oxy-methyl-3-isopropyl-8-methyl-1,2,3,3a,4,5,5a,6,7,10,10a,10b-dodeca-hydro-7,10-endo-epidi-oxy-cyclo-hepta-[e]indene-3a-carb-oxy-lic acid], C(22)H(32)O(6) (I), is closely related to methyl 5a-acet-oxy-methyl-3-isopropyl-8-methyl-1,2,3,3a,4,5,5a,6,7,10,10a,10b-dodeca-hydro-7,10-endo-epidi-oxy-cyclo-hepta-[e]indene-3a-carboxyl-ate, (II) [Brito et al....

In the title compound, C36H30N4O3, the quinoxaline-indene system is roughly planar, with a maximum deviation from the mean plane of 0.218 Å for the C atom shared with the central pyrrolidine ring. This latter ring forms dihedral angles of 84.54 (7) and 83.91 (8)° with the quinoxaline-indene system and the indole ring, respectively. The central pyrrolidine ring has an envelope conformation with ...