| 主权项 |
1. A process for the preparation of a compound of formula (I) or a salt thereof, wherein a compound of formula (II) or a salt thereof is hydrogenated (e) in the presence of a catalyst comprising iridium; or (f) in the presence of a catalyst comprising ruthenium and a compound of: formula (IV), or formula (VII), wherein R3 is alkyl, cycloalkyl or aryl; R4 is cycloalkyl, aryl or heteroaryl; R5 is cycloalkyl or aryl; R6 is cycloalkyl or aryl; R7 is cycloalkyl or aryl; R8 is cycloalkyl or aryl; and R9 is cycloalkyl or aryl. |
