According to the retrosynthetic perspective, the title totalsyntheses were accomplished by employing the regioselective Diels-Alder reactions of the (+)-naphthoquinone (5), the CDEF-ring system of nogalamycin congeners, with various structural types of dienes (8, 16, and 26). The highly functionalized dienes (16 and 26) incorporating all the functionalities present in the A-rings of (+)-7-deoxynogarol
根据逆向合成的观点,标题总合成是通过使用(+)-萘醌(5),诺加霉素同类物的CDEF环系统,具有不同结构类型的二烯的区域选择性Diels-Alder反应来完成的(8,16和26)。通过以下方法有效地制备了高度官能化的二烯(16和26),该化合物结合了(+)-7-脱氧炔诺醇(3)和(+)-7- con - O-甲基-壬醇(2)的A环中存在的所有官能团1,4-环己二烯和2-环己酮衍生物(6和21)的合成方式。还讨论了关键Diels-Alder反应的反应机理。
Total syntheses of (+)-nogarene and (+)-7,8-dihydronogarene
Total syntheses of the title compounds, the simplest and the hitherto unknown novel nogalamycin congeners, were first accomplished by elaborating the CDEF-ring system () from the methylketone () and subjecting to regioselective Diels-Alder reaction with the bistrimethylsilyl keteneacetal ().