| abstract |
The present invention provides a compound having a steroid C 17,20 -lyase-inhibitory activity and useful for the therapy and prophylaxis of tumor such as prostatism, breast cancer and the like, and a method for efficiently separating an optically active compound of this compound from a mixture of optical isomers thereof, a compound of the formula: n nwherein each symbol is as defined in the specification, a salt thereof or a prodrug thereof, and a method for obtaining an optically active compound by optically resolving a mixture of optical isomers by the use of a resolving agent such as tartranilic acid and the like. |