In the title compound, C(18)H(13)N(3)O(2), the benzene rings form a dihedral angle of 78.49 (9)°. The dihedral angles between the benzene rings and the pyrimidine ring are 76.53 (10) and 27.73 (11)°. The two cis-fused six-membered heterocyclic rings adopt half-chair confirmations. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming chains parallel to the b axis.

The title eremophilenolide, C(15)H(22)O(3), is a natural compound isolated from Senecio laetus Edgew. The two cis-fused six-membered rings have chair confomations and the five-membered ring has a planar envelope conformation [maximum deviation = 0.010 (1) Å]. The β-hy-droxy group participates in inter-molecular O-H⋯O hydrogen bonding, forming mol-ecular chains along the a axis.

Here, we describe a new and simple synthetic strategy to various polycyclic sulfones via Diels-Alder reaction and ring-rearrangement metathesis (RRM) as the key steps. This approach delivers tri- and tetracyclic sulfones with six (n = 1), seven (n = 2) or eight-membered (n = 3) fused-ring systems containing trans-ring junctions unlike the conventional all cis-ring junctions generally obtained d...

In the title compound, C17H12Cl4FNO4, the configuration of the cyclo-alkene skeleton is endo,cis. The benzene ring is twisted by 71.01 (11)° from the attached pyrrolidine ring. In the crystal, one of the methine groups of the fused-ring system forms a weak C-H⋯O hydrogen bond. The other methine groups participates in a C-H⋯F inter-action to the same adjacent mol-ecule. Together, these generate ...

A sequential Diels-Alder reaction/silicon-directed [4 + 2]-annulation was developed to assemble hydroisochromene-type ring systems from menadione 2. In the first step, a Diels-Alder of the 1-silyl-substituted butadiene 1 with 2 furnished an intermediate cyclic allylsilane. Subsequently, TMSOTf promoted a [4 + 2]-annulation through trapping of an oxonium, generated by condensation between an ald...

The biodegradation of polycyclic aromatic hydrocarbon pollutants is constrained, in part, by their solid physical state and very low water solubility. Searching for ways to overcome these limitations, we isolated from soil a bacterium capable of growing on pyrene as a sole source of carbon and energy. Acid-fast stain, morphology, and fatty acid profile identified it as a Mycobacterium sp. In a ...

A synthetic sequence is described for construction of the tricyclic portion (35) of kempane diterpenes. The central stereochemistry was established by a Diels-Alder addition of 2,6-dimethyl-para-benzoquinone to a 5-membered, dithiane-protected diene, and the addition of acetylide, with very high chemoselectivity, provided a suitably functionalized handle that will be incorporated into the final...

Synthesis of novel polyhydroxylated derivatives of decalin is described. The presented methodology consists in a one-pot copper-catalyzed 1,4-addition of vinylmagnesium bromide to sugar-derived cyclohexenone, followed by an aldol reaction with a derivative of but-3-enal. The obtained diene is then subjected to an assisted tandem catalytic sequence: ring-closing metathesis with the subsequent re...