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The structurally intriguing terpenes pallambins C and D have been assembled in only 11 steps from a cheap commodity chemical: furfuryl alcohol. This synthesis, which features a redox-economic approach free of protecting-group manipulations, assembles all four-ring systems via a sequential cyclization strategy. Of these fourring constructing operations, two are classical (Robinson annulation and Mukaiyama aldol) and two are newly devised. During the course of this work a method for the difunctionalization of enol ethers was developed, and the scope of this transformation was explored. [ABSTRACT FROM AUTHOR]

Twenty marine-engine lubricants from five Japanese oil companies were discriminated on the basis on a hopane analysis using a gas chromatograph−mass spectrometer (GC−MS). The hopane ratios of 18α-22,29,30-trisnorneohopane (1) to 17α-22,29,30-trisnorhopane (2) and of 17α-21β(H)-norhopane (3) to 17α-21β(H)-hopane (5) were determined. Each lubricant can be discriminated by combining the figures represented by the 1to 2and 3to 5ratios and principal component analysis from 1through (22R)-17α-21β(H)-29-pentakishomohopane (15). Oleanane (4), one of the biomarkers inherent in the crude oils from Southeast Asia, has been detected in the lubricants of eight out of 20 types, and 4represents a significant feature for the discrimination. The discrimination of the lubricants in the spilled oils was also investigated. [ABSTRACT FROM AUTHOR]

A general preparation method of the all-(E)-polyprenols 12 has been developed from readily available geranyl sulfone by the chain-extension process utilizing the C5 unit 5 and the chain-termination process utilizing the C5 unit 10 together with the chemoselective reductive desulfonylation. The polyprenols 12 were converted to compounds 3 containing two consecutive prenyl sulfone moieties at the tail end, which underwent the controlled electrophilic cyclization only at the carbon-carbon double bonds that were remote from the flat and rigid benzenesulfonyl groups. [ABSTRACT FROM AUTHOR]

The article discusses the catalytic reaction that help convert carbohydrates, vegetable oils, animal fats, and terpenes into valuable chemicals and fine chemicals. It focuses on chemical routes through heterogeneous catalysis and to describing catalytic processes that is not harmful to the environment as an alternative to the old processes.

The first total synthesis of an (E)-cladiellin diterpene, (-)-cladiella-6,11-diene-3-ol (1), was accomplished featuring an intramolecular amide enolate alkylation-intramolecular Diels-Alder strategy. In addition, a highly stereo-, regio-, and chemoselective synthetic strategy for other members of the cladiellin diterpenes such as (+)-polyanthellin A (2), (-)-cladiell-11-ene-3,6,7-triol (3), and (-)-deacetoxyalcyonin acetate (4) was developed utilizing the synthetic (E)-cladiellin 1 as a common intermediate by taking advantage of the unique chemical properties of its C(6)-(E)-oxatricyclic skeleton. [ABSTRACT FROM AUTHOR]