Free radical allyl transfers utilizing soluble non-cross-linked polystyrene and carbohydrate scaffold supports

[GRAPHICS] Free radical allylations were studied using (1) soluble non-cross-linked po lystyrene supports, (2) carbohydrate scaffolds, and (3) a combination of bo th synthetic motifs, Allylations on these custom designer supports provide easily purified products, free of tin residues. A D-xylose carbohydrate sca ffold bearing a bromoester was used for a diastereoselective allyl tin tran sfer thermally at 80 degrees C and with Lewis acids. This is the first exam ple of a diastereoselective radical reaction directed by a removable polyme r-supported carbohydrate auxiliary.