RECENT DEVELOPMENTS IN THE SYNTHESIS OF DRIMANE AND LACTARANE SESQUITERPENES

Several new methods for the construction of ene-dialdehyde functionali ties and for the regioselective annulation of butenolides were develop ed and applied in the synthesis of drimane and lactarane sesquiterpene s. Optically active drimanes were synthesised starting from S-(+)- and R-(-)-carvone. A new development in this approach starts with a conju gate addition of cyanide to the enone in carvone, followed by an annul ation reaction. Base-induced and directed reactions of substituted tra ns - perhydronaphthalene-1,4-diol monosulfonate esters in apolar solve nts provide an effective route to cis - perhydroazulene systems. The r earrangement can be directed towards intramolecular ether formation. B ased on this approach a total synthesis of lactaranes is under investi gation.