OXIDATION OF 3-TRIBUTYLSTANNYL-1-ALKENYL CARBAMATES WITH SELENIUM DIOXIDE

Selenium dioxide oxidation reaction of (Z)-3-tributylstannyl-1-alkenyl carbamates, easily obtained from allylic carbamates precursors via Bu li/TMEDA/Ti((OPr)-Pr-i)(4) metallation, results in formation of the co rresponding S-hydroxy-1-alkenyl carbamates in high yield. No trace of the corresponding oxo derivatives was detected. Under stoichiometric c onditions, simple allyltin or (Z) or (E)-crotyltin carbamates cleanly afford the corresponding (E)-allylic alcohols whereas less stereoselec tive reactions are observed with more complex substrates.