In the BF3-catalyzed allylation of quinones with allylstanyl reagents,(Z)-2- hexenyltributylstannane (3) is introduced with no retention of the original double-bond stereochemistry, and neryl reagent (5) is introduced with partial loas of olefin stereochemistry. In contrast,(E)-2-hexenyltributylstannane (4) and geranyltributylstannane (6) are introduced with complete retention of their olefin geometries.