Study On The Synthesis Of Steroidal C-7 Derivatives From AD/DHEA

Steroids play an important role in the medical field for their special bioactivities such as strong anti-inflammatory activity, anti-cancer cell and anti-HIV acitivity. In recent years, steroid drugs are widely used to treat rheumatism, cardiovascular diseases, endocrine disorders, cancer, Alzheimer's and other diseases. Therefore, studies of the steroids and their intermediates have important theoretical and practical value. This thesis was focused on the synthesis of important steroid intermediate 3β, 7β-dihydroxyl-5-androstene-17-one and new 3,17-dioxo-5-androstene-7β-ether steroid derivatives.(1) Starting from dehydroepiandrosterone(DHEA),compound 3β, 7β-dihydroxyl -5-androstene-17-one was synthesized by a route which involved C3 esterification, ketal reaction at C17, oxidation at C7, reduction at C7 with stereo-selectivity, deketalization at C17 and alkaline hydrolysis at C3. All their structures were identified with MS,1H NMR and IR spectrum. The influence factors of the above reactions were studied to find the optimal conditions and the stereo-selectivity and mechanisms of oxidation and reduction at C7 were discussed.(2) Starting from Androstenedione(AD), 3,17-dioxo-5-androstene-7β-ether steroid derivatives were synthesized by a seven-step route which involved ketal reaction at C3 and C17,oxidation at C7,reduction at C7 with stereo-selectivity, etherification at C7, deketalization at C3 and C17 in reactions. All their structures were identified with MS,1H NMR and IR spectrum. The Influence factors were studied to find the optimal reaction conditions,and the probable mechanisms stereo-selectivity reduction at C7 was discussed.