The BF3-mediated nucleophilic addition of 2- and 4-methoxymethyl-2,4-pentadienylstannanes to aldehydes selectively gives the corresponding γ adducts, while the reaction with sterically hindered aldehydes affors the corresponding ε adducts regardless of the tin reagents applied.
Synthesis of naturally occuring quinones. Part 20. Tandem Michael/Diels-Alder addition as a new strategy toward tetracyclic systems: synthesis of 11-deoxyanthracyclinones
Electrophilic trapping of the pentadienylanions bearing a methoxymethyl group with Me3SnBr gives Z-pentadienylstannanes in high regioselectivity regardless of the structure of the anion.