An N-alkylamide profiling from an ethanolic Anacyclus pyrethrum DC. root extract was performed using a gradient reversed phase high performance liquid chromatography/UV/electrospray-ionization ion-trap mass spectrometry (HPLC/UV/ESI-MS) method on an embedded polar column. MS1 and MS2 fragmentation data were used for identification purposes while UV was used for quantification. Thirteen N-alkyla...

A phytochemical investigation of the New Zealand endemic Apiaceae species Anisotome lyallii Hook.f. yielded (+)-alpha-angeloyloxylatifolone (1), 6-O-angeloyl-8-O-tigloyl-6beta,8alpha,11-trihydroxygermacra-1(10)E,4E-diene (2), 6-O-tigloyl-8-O-tigloyl-6beta,8alpha,11-trihydroxygermacra-1(10)E,4E-diene (3) and 6-O-tigloyl-8-O-tigloyl-1alpha,6beta,8alpha,11-tetrahydroxygermacra-4E,10-(14)diene (4)....

In the title complex, [PdBr(2)(C(7)H(8))], the Pd(II) ion lies in a distorted square-planar environment defined by the two Br atoms and the mid-points of the two π-coordinated double bonds of bicyclo-[2.2.1]hepta-2,5-diene. The complex is disposed about a crystallographic mirror plane parallel to the ac plane passing through the Pd, Br atoms and the centre of the diene ligand.

Two new triterpenoids, 30-O-beta-D-glucopyranosyloxy-2alpha,3alpha,24-trihydroxyurs-12,18-diene-28-oic acid O-beta-D-glucopyranosyl ester (1) and 2alpha,3beta,3,30-tetrahydroxyurs-12,18-diene-28-oic acid O-beta-D-glucopyranosyl ester (2) were isolated from roots of Actinidia valvata Dunn. Their structures were elucidated by means of extensive spectroscopic studies. Both these two new compounds ...

The title compound, C(13)H(18)Br(2)O(3), was prepared by a bromination reaction of (1E,3Z)-methyl 5-oxocyclo-octa-1,3-diene-carboxyl-ate, which was obtained by an ep-oxy-dation reaction of tert-butyl cyclo-oct-1,3-diene-carboxyl-ate. The crystal structure confirms unequivocally the absolute configuration of both chiral centres to be S. In the crystal, C-H⋯O inter-actions link the mol-ecules int...

The intramolecular Diels-Alder reactions of cycloalkenones and terminal dienes occur with high endo stereoselectivity, both thermally and under Lewis-acidic conditions. Through computations, we show that steric repulsion and tether conformation govern the selectivity of the reaction, and incorporation of either BF3 or α-halogenation increases the rate of cycloaddition. With a longer tether, iso...

The mol-ecule of the title compound, C(66)H(40)F(6)·CH(2)Cl(2), is centrosymmetric; the dihedral angle between the central fluorinated unit and the cyclo-penta-diene ring is 88.36 (7)°. The dihedral angles between the cyclo-penta-diene ring and the four surrounding phenyl rings are in the range 26.6 (1)-65.6 (1)°. Centrosymmetric cavities in the crystal structure are populated by disordered dic...

The reaction energetics of 280 polar Diels-Alder (DA) reactions between 70 dienophiles and 4 dienes have been studied in detail using the B3LYP/6-31G* level of theory, combining conceptual density functional theory (DFT) analysis and the distortion/interaction model. The barrier heights are governed by a fine balance between the energy required to distort the reactants from their initial to the...