A new asymmetric synthesis of (R)- and (S)-3-arylphthalides: Extremely high diastereoselective reaction of arylcarbaldehydes with chiral [2-(1,3-oxazolidin-2-yl)phenyl]titanium ate complexes
Chiral [2-(1,3-oxazolidin-2-yl)phenyl]titanium ate complexes are prepared from the corresponding lithium complexes, and the extremely high diastereoselective reaction of arylcarbaldehydes with the chiral titanium ate complexes is performed. Then, optically pure (R)- and (S)-3-arylphthalides are synthesized in favorable yields and the chiral auxiliary reagents are recovered with no less of the optical purity.