Stereoselective total synthesis of dodecagalacturonic acid, a phytoalexin elicitor of soybean.

O-(alpha-D-Galactopyranosyluronic acid)-[(1----4)-O-(alpha-D-galactopyranosyluronic acid)]10-D-galactopyranuronic acid (1), an endogenous elicitor of the phytoalexin of soybean, was synthesized by way of highly stereoselective glycosylations that involved glycosyl fluorides as the donors and oxidation of the twelve primary hydroxyl groups in the alpha-(1----4)-linked galactododecaoside derivative.