enecyclohex-2-ene 9 gave the corresponding endo tricarbocycle bearing of sp2 carbon on the bridge-head position. Phenylthio and methoxy derivatives of 9, e.g. 11 and 12, also underwent similar cyclization to afford the endo tricarbocyclic products 13 and 14 in high yields. Further, the stereochemistry of the substituents on 8-membered ring has been completely controlled in a desired manner in every