[GRAPHICS] Tricyclohexylphosphine, Cy3P, in conjuction with [(C3H5)PdCl](2) catalyzes allylic alkylation of terminal allylic acetates with high regioselectivity toward branched products, which is in contrast to most other palladium catalysts. Other ligands, even those of similar basicity or bulkiness, did not show the same regioselectivity. Alkylation of 1,4-diacetoxy-2-butene gave predominantly branched products which had not been observed previously.