ASymmetricβ- Lactones H H 1-2 mol% quinidine Clc H toluene,-25°C O 89% yield Clc (S)98%ee Requires electron deficient aldehydes and aromatic ketones 68-98%yied 89-98%ee Alkyl aryl ketones react in trace amounts Staring, E.G.J.: Wynberg, H.J. Am. Chem. Soc. 1982, 104, 166 Staring, E.G. J; Wynberg, H J. Org. Chem. 1985, 50, 1977Asymmetric b-Lactones Staring, E. G. J.; Wynberg, H. J. Am. Chem. Soc. 1982, 104, 166. Staring, E. G. J.; Wynberg, H. J. Org. Chem. 1985, 50, 1977. O Cl 3 C H O H H O O Cl 3 C + 1-2 mol% quinidine toluene, -25 °C 89% yield (S) 98% ee Requires electron deficient aldehydes and aromatic ketones 68 – 98% yield 89 – 98% ee Alkyl aryl ketones react in trace amounts