Compounds of formula (I) wherein R1, R2, R3, R4, R5, R23, R24, L, A and B are as defined in claim 1, or pharmaceutically acceptable salts thereof are disclosed. The compounds of formula (I) possess utility as cytochrome P450 monooxygenase 11A1 (CYP11A1) inhibitors. The compounds are useful as medicaments in the treatment of steroid receptor, particularly androgen receptor, dependent diseases and conditions, such as prostate cancer.本文揭露式(I)化合物其中R1、R2、R3、R4、R5、R23、R24、L、A和B係如於申請專利範圍第1項中定義的、或其醫藥上可接受的鹽。式(I)化合物具有作為細胞色素P450單氧化酶11A1(CYP11A1)抑制劑的實用。該等化合物可於類固醇受體(特別是雄性素受體)依賴性疾病和病況(諸如前列腺癌)之治療中用作為醫藥品。