| 摘要 |
The present invention relates to a process for preparing a compound of Formula (Vl), wherein R1 and R6 are hydrogen, substituted or unsubstituted alkyl substituted or unsubstituted aryl, or substituted or unsubstituted aralkyl; R5 is OR2, NR2R3, SR2, B (OR2)(OR3), or X" selected from F, Cl, Br, I, OCOR2, OSO2R2, wherein R2 and R3 independently from each other represent substituted or unsubstituted alkyl, substituted or unsubstituted aryl, or substituted or unsubstituted aralkyl; or R2 and R3 cooperatively form a part of a 5- to 10-membered fused or unfused ring, optionally a chiral 5- to 10- membered fused or unfused ring; X is selected from F1 Cl, Br, I; and * indicates a chiral center; by hydrogenation of a compound of Formula (V), wherein R1, R5, R6 and X are as defined above; wherein hydrogenation is conducted in the presence of a catalyst selected from complexes comprising at least one transition metal, wherein dehalogenation occurs in less than 10 molar % relative to the molar amount of the compound of formula Vl. |
