A DRAMATIC EFFECT OF THE REACTION CONDITIONS ON THE COURSE OF A PALLADIUM-CATALYZED CYCLIZATION OF AN ALKENE BEARING A VINYL BROMIDE AND A NUCLEOPHILE - A NEW ROUTE TO THE TRANS-HYDRINDANE SYSTEM

Upon treatment with catalytic Pd(dppe) in the presence of KH, the malo nate derivative 3 underwent a Wacker-type cyclization leading exclusiv ely to compound 4 having the trans-hydrindane system. However, the cou rse of the cyclization is dramatically dependent on the reaction condi tions, mainly on the nature of the base. In the presence of a carbonat e, a quaternary ammonium salt and the catalytic system (Pd(OAc)(2) + P Ph3) the cyclization of the same substrate 3 led only to compounds res ulting from an initial Heck reaction of the vinyl bromide on the neigh bouring olefin.