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Nonactivated trienes and aryltrienes were cyclized into polycyclic compounds in good to excellent yields under bismuth triflate catalysis in a biomimetic fashion. The reaction showed broad applicability and allowed for the formation of functionalized bicyclic to tetracyclic structures from simple precursors in one pot. For some specific substrates, the cyclization was followed by a methyl shift as encountered in terpenoid biosynthesis. [ABSTRACT FROM AUTHOR]

The kinetics of limonene epoxidation catalyzed by PW-Amberlite under triphasic conditions is described. A mechanistic pathway was postulated, and a heterogeneous kinetic model was derived following pseudo-stationary-state theory. Using adsorption parameters that were estimated from independent binary adsorption experiments, the resulting kinetic model fitted the experimental data quite well. [ABSTRACT FROM AUTHOR]

We describe a novel convergent procedure that has proved useful in the synthesis of a wide range of meroterpenoid-related structures containing a mono-, ses- qui-, or diterpenoid moiety linked to a nonfused aromatic subunit with various substitution patterns. The key steps were the Stille-type coupling of aryl stannanes and allylic carbonates, followed by the titanocene-catalyzed domino cyclization of aryl epoxypolyprenes. The coupling reaction was perfectly compatible with preformed epoxides, while the sequential cyclization, which presumably proceeded via alkyl radicals inert to benzene derivatives, selectively provided exocyclic alkenes. [ABSTRACT FROM AUTHOR]