posted on 1997-03-21, 00:00authored byMichael M. Ott, R. Daniel Little
A new and efficient entry to the ABC-ring system common
to taxol and related materials has been
developed. Highlights include the use of a regioselective
intramolecular diyl trapping reaction to
synthesize tricyclic alkene 5, the creation and oxidative
cleavage of the tetrasubstituted olefin found
in ketal 20a,b to afford a highly functionalized
eight-membered ring (21a), and cyclization of
22,
thereby providing the tricyclic core.