Enantiopure β-methoxy carboxyl derivatives from a chiral titanium enolate and dimethyl acetals

Lewis acid-mediated reaction of the titanium enolate arising from (S)-N-acetyl-4-isopropyl-1,3-thiazolidine-2-thione with dimethyl acetals furnishes β-methoxy carboxyl adducts in good yields and stereoselectivities. The adducts can be, in turn, transformed into a wide range of enantiopure α-unsubstituted β-methoxy carboxyl derivatives in excellent yields.