The regioselective effect of the allylic silicon or oxygen atom in 1,3-dipolar cycloaddition of nitrones.
1,3-Dipolar cycloaddition 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.