benzofurans has been researched along with ketene* in 3 studies
3 other study(ies) available for benzofurans and ketene
| Article | Year |
|---|---|
The photoformation of a phthalide: a ketene intermediate traced by FSRS.
The photo-isomerization of o-acetylbenzaldehyde (oABA) in acetonitrile was studied by femto- and nanosecond transient absorption spectroscopy. Spectroscopic signatures are assigned with the aid of TD-DFT, TD-CAM-DFT and DFT-MRCI computations. The isomerization yields a lactone, 3-methylphthalide (3MP), with a quantum yield of 0.3 (30%). As evidenced by femtosecond stimulated Raman spectroscopy (FSRS), the isomerization proceeds via a ketene intermediate. It is formed within ∼2-3 ps after photo-excitation. Intersystem crossing (ISC) populating the triplet state of oABA seems to compete with the ketene formation. Experiments on the non-reactive meta- and para-derivatives, which undergo efficient ISC with time constants of 5 ps, support this statement. The triplet state of oABA also contributes to the ketene formation, presumably involving a biradical intermediate. The ketene exhibits a lifetime of 1.4 μs and generates an additional intermediate in the cascade towards the lactone. Topics: Benzaldehydes; Benzofurans; Ethylenes; Isomerism; Ketones; Lactones; Light; Quantum Theory; Spectrum Analysis, Raman | 2015 |
Stereoselective synthesis of the rocaglamide skeleton via a silyl vinylketene formation/[4 + 1] annulation sequence.
The tricyclic core of the cyclopentabenzofurans has been prepared in an efficient and stereoselective manner utilizing an intramolecular silyl vinylketene formation/[4 + 1] annulation sequence. This novel approach affords the ABC ring system where the adjacent phenyl and aryl substituents of the C ring have the required cis relationship. Topics: Animals; Benzofurans; Ethylenes; Ketones; Mice; Silanes; Stereoisomerism; Substrate Specificity; Vinyl Compounds | 2008 |
Ketene acetal and spiroacetal constituents of the marine fungus Aigialus parvus BCC 5311.
Aigialone (1) and aigialospirol (2), two structurally unique compounds, were isolated from the mangrove fungus Aigialus parvus BCC 5311. The structure of the new ketene acetal 1 was elucidated by spectral analysis, and its relative stereochemistry was determined by X-ray crystallography. The stereochemistry of aigialospirol (2), elucidated by NMR spectral analysis, suggested that this compound is possibly derived from hypothemycin (3), a metabolite previously isolated from this same fungus. Topics: Acetals; Ascomycota; Benzofurans; Crystallography, X-Ray; Ethylenes; Ketones; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Stereoisomerism; Thailand; Zearalenone | 2004 |