Stereocontrolled Diels−Alder Cycloadditions of Sugar-Derived Dihydropyranones with Dienes
作者:Christian A. Iriarte Capaccio、Oscar Varela
DOI:10.1021/jo020309w
日期:2002.11.1
dihydropyranone. The influence of other catalysts (BF(3) or iodine) employed for the glycosylation on the optical purity of the dihydropyranone was studied. Enantiomericallypure dihydropyranones 8b and 9c were obtained using chiral alcohols ((R)- and (S)-2-octanol, respectively) as glycosylating agents. Compounds 8a,b and 9a,c proved to be reactive dienophiles in thermal and Lewis acid-promoted Diels-Alder
Reactions of Diels–Alder adducts of a sugar-derived dihydropyranone leading to fused polycyclic compounds
作者:Christian A. Iriarte Capaccio、Oscar Varela
DOI:10.1016/j.carres.2004.01.008
日期:2004.4
having three or four fused rings. Reduction of the carbonyl group of the butadiene adduct (2) took place with low facial selectivity affording the alcohols 5 and 6 in 1:1.4 ratio. In contrast, a higher diastereoselection was observed for the reduction of the carbonyl of the cyclopentadiene adducts 3 and 4 to give the endo alcohols 10 and 13, respectively. The epoxidation of 6 showed low facial selectivity