A novel synthetic approach towards the stereoselective synthesis
of the C6-C18 fragment of the biologically active antitumor
agent scytophycin C is described. The synthesis involves Marouka allylation,
base-catalyzed intramolecular conjugate addition, Wittig olefination,
and a tandem allylation.
scytophycin - allylation - olefination -
trans-2,6-disubstituted dihydropyran