Synthesis of Phosphonomethyl Tetrahydrofurans via the Mori-Tamaru Reaction of Phosphonodienes.

Nickel-catalyzed reductive addition of phosphono-dienes to aldehydes (the Mori-Tamaru reaction) gives hydroxyvinyl phosphonates in good yields with excellent control of the relative stereochemistry. Base-induced cyclization of the vinyl phosphonates yields phosphonomethyl-substituted tetrahydrofurans. Inversion of the hydroxyl stereochemistry by Mitsunobu reaction and then cyclization yields a different set of phosphonomethyl-substituted tetrahydrofuran diastereoisomers.