342793-69-5Relevant academic research and scientific papers
Stereoselective synthesis of (E)-4-alkylidenecyclopent-2-en-1-ones by a tandem ring closure-Michael addition-elimination
Ballini, Roberta,Bosica, Giovanna,Fiorini, Dennis,Gil, Maria Victoria,Petrini, Marino
, p. 1265 - 1267 (2007/10/03)
(equation presented) Reaction of (Z)-1,4-diketones with various functionalized nitroalkanes in the presence of DBU gives 4-alkylidenecyclopent-2-en-1-ones with E selectivity. A cyclopentadienone intermediate is probably formed by intramolecular aldol cond
Novel Oxa-Cage Compounds: Synthesis, Structures, and the Formation Mechanism of Tetraacetal Oxa-Cages and Convex Tetraquinane Oxa-Cages
Wu, Hsien-Jen,Lin, Chu-Chung
, p. 7558 - 7566 (2007/10/03)
Several novel tetraacetal oxa-cage compoundsa 5a-d and convex tetraquinane oxa-cage compounds 16a-d and 17b-d are synthesized from alkylfuranes in three steps.Ozonolysis of the cis-endo-1,4-diones 3a-d in dichloromethane at -78 deg C followed by reduction with dimethyl sulfide gives the oxa-cage 5a-d in high yields, respectively.The structures of these new tetraacetal oxa-cages are deduced from their spectral data and proven for the first time by X-ray analysis of the crystalline compound 5a.Ozonolysis of 3a-d in dichloromethane at -78 deg C followed by treatment with triethylamine gives the convex tetraquinane oxa-cages 16a-d and 17b-d in 85-90percent yields, respectively.The structures of these novel convex tetraquinane oxa-cages are finally proven by X-ray analysis of the crystalline compound 16a.Two reaction mechanisms via the common final ozonides are proposed for the formation of these two different types of oxa-cage compounds.The structures of the final ozonides formed by ozonolysis of the norbornene derivatives 3 are deduced to be 9 with endo stereochemistry on the basis of their spectral data and the formation of these two types of oxa-cages from the final ozonides.In reaction with the final ozonides, triethylamine is found to act as a base instead of a reducing agent, a different function from that of dimethyl sulfide.The synthesis of oxa-cages 24 and 25, which possess aromatic substituents dirctly on the skeleton, has also been accomplished.
