A general route to enantiopure spirocarbocycles is described. The use of va
rious chiral bicyclic lactams 1 that have been doubly alkylated with olefin
ic halides gives good yields of alpha,alpha -disubstituted chiral lactams 2
which were cyclized to spiro-olefins using ring closure metathesis methodo
logy (Grubbs' catalyst). These spirolactams 3, formed in generally excellen
t yields, were shown to be smoothly transformed into spirocyclopentenone 6,
spirocyclohexenone, 7, and spirolactams 8. Further demonstration of this s
pirocyclization methodology was featured in a formal synthesis of zizaene,
by preparing in enantiomeric form the Coates' intermediate 21. This synthet
ic effort provided additional examples of the synthetic versatility of chir
al bicyclic lactams 2a,b.