The reaction of (2S, SS)-α-(1-hydroxyethyl) vinyl sulfoxide with alkyl radicals and tributyltin hydride gave the addition-hydrogenation products with high diastereoselectivity, whereas (2R, SS)-α-(1-hydroxyethyl) vinyl sulfoxide gave no products under similar conditions. An important role of intramolecular hydrogen bonding for the diastereoselectivity as well as the reactivity toward alkyl radicals is discussed.
