Electrophilic α-formylation of carbonyl compounds using norephedrine-derived 2-metohoxy oxazolidines. A novel asymmetric formation of quaternary stereocenters

Article abstract of DOI:10.1016/S0040-4039(00)97587-7

The BF₃·Et₂O promoted addition of enamines and silylenolethers, to the nor-ephedrine-derived orthoamides 1 or 5 has been studied. A judicious choice of the type of nucleophile and electrophile leads to useful selectivities. When a quaternary α-carbonyl stereocenter is created, the direct removal of the chiral auxiliary is possible and renders the overall process an efficient asymmetric carbonyl α-formylation.