| abstract |
The present invention relates to an optically pure (+)-trans enantiomer of a compound represented by the following formula (I) and an optically pure intermediate of the compound: Wherein, R 1 , R 2 , R 3 , R 4 and R 9 are as defined in the description; it also relates to a method for preparing the optically pure compound and its intermediate, and also relates to a pharmaceutical composition containing the optically pure compound . The compounds represented by formula (I) can be used to treat diseases or diseases mediated by the inhibition of cyclin-dependent kinases, such as cancer. |