abstract |
Described is a process for preparing chiral compounds of the formula <IMAGE> wherein X1 and X2 are independently F or Cl, and Y is Cl, Br or I, comprising reacting a triol of the formula <IMAGE>etone in the presence of a catalyst, then with a halogen selected from Cl2, Br2 or I2, or N-bromosuccinimide or N-iodosuccinimide. |