SYNTHETIC STUDIES ON THE 1,6-METHANO[10]ANNULENE SKELETON - A NEW ROUTE THAT PROVIDES DERIVATIVES SUBSTITUTED AT THE BRIDGE AND ON THE ANNULENE RING

A new synthetic route to the 1,6-methano[10]annulene skeleton has been developed. The key step in this route is the semi-benzylic Favorskii rearrangement of a [4.4.2]propellane to a [4.4.1]propellane. The metho dology discussed here provides access to 1,6-methano[10]annulene deriv atives bearing substituents on both the bridge carbon and the annulene ring. Control of the relative positioning of these appendages is achi eved by introducing the annulene substituent via cuprate addition to a n allylic lactone.