NEW STUDIES AND A REINVESTIGATION ON [4-)-THEBAINE - ASYMMETRICAL DIELS-ALDER REACTIONS WITH A CONFORMATIONALLY FIXED CHIRAL DIENE(2] CYCLOADDITIONS OF ()
U. Pindur et D. Keilhofer, NEW STUDIES AND A REINVESTIGATION ON [4-)-THEBAINE - ASYMMETRICAL DIELS-ALDER REACTIONS WITH A CONFORMATIONALLY FIXED CHIRAL DIENE(2] CYCLOADDITIONS OF (), Liebigs Annalen der Chemie, (9), 1993, pp. 947-953
Some novel Diels-Alder reactions of the opium alkaloid (-)-thebaine (1
) as an electron-rich diene and a reinvestigation of its reactions wit
h cyclic and acyclic dienophiles are described. The pi-facial selectiv
ity has been studied on the basis of structural analyses of the cycloa
dducts. Some related results on [4 + 2] cycloaddition reactions of 1-m
ethoxy-1,3-cyclohexadiene (11) are also reported.