New types of norcantharimide analogues were prepared by three
methods: epoxidation, photooxidation, and bromination. Epoxidation
of deoxynorcantharimide with m-chloroperoxybenzoic acid
gave an isomeric mixture. The selective formation of the syn-isomers was attributed to dipole-dipole
interactions between the peracid and imide moiety. Photooxidation
of deoxynorcanthamide gave syn- and anti- hydroperoxide analogues through
ene addition of singlet oxygen; the anti-hydroperoxide
was the major product in this case, as a result of the steric effect
of the imide ring. Bromination of deoxynorcantharimide and subsequent
transformations gave a pyrrolidine and the phthalimide core structure.
ene reactions - epoxidation - photooxidations - halogenation - stereoselective synthesis
- heterocycles
