1,3-Dipolarcycloaddition of nitrones on several allyl silanes, allyl ethers, and allyl alcohol was investigated. The silicon atom in dipolarophiles controlled the regioselectivity in favor for 5-(silylmethyl)isoxazolidines, while the oxygen atom for 4-(alkoxymethyl)isoxazolidines.
Metal ion-mediated diastereoface-selective nitrone cycloadditions. Reaction mechanism for the reversal of regloselectivity observed in the magnesium and zinc ion-mediated nitrone cycloadditions of allylic alcohols
Magnesium and zinc ion-mediated cycloadditionreactions of a carbonyl-conjugated nitrone, (Z)-N-(benzoylmethylene)aniline N-oxide to the allylicalcohols bearing a chirality at α-position give isoxazolidine-5-alcohol and isoxazolidine-4-alcohol derivatives, respectively, both in highly lk-1,2-inductive manners. α,α-Disubstitution of allylicalcohol dipolarophiles virtually inhibits the zinc ion-catalyzed