【作者】 程斌；

【导师】 翟宏斌；

【作者基本信息】 中国科学技术大学 ， 有机化学， 2009， 博士

【摘要】 本论文分为三个部分：（1）NakadomarinA的全合成研究，（2）SubincanadineC的全合成研究，（3）含氟尼古丁类似物的合成研究。Nakadomarin A是日本科学家Kobayashi于1997年从日本冲绳县（Okinawa）庆良间列岛（Kerama Islands）的一种海绵Amphimedon sp.（SS-264）中分离得到了一种新型Manzamine类海洋生物碱。它具有完全环状结构8/5/5/5/15/6六环体系，其中一个环为呋喃环，并具有一定的生理活性。通过醛1-98和炔丙胺盐酸盐的还原氨化反应以及随后的与碘代呋喃1-94的Sonogashira偶联反应实现三个片段的连接，用PtCl₂催化的串联反应构建了（-）-Nakadomarin A核心四环结构。通过双RCM路线完成了八元环（E环）和十五元环（F环）的构建，实现了（-）-NakadomarinA的全合成。为了解决RCM路线构建十五元环（F环）顺反异构的比例较差的问题，采用Wittig反应构建顺式双键，分子内SN2反应或还原氨化形成C-N键构建十五元环做了很多有意义的尝试。Subicanadines C是由日本科学家Kobayashi等人于2002年从巴西的一种药用植物（Aspidosperma subincanum Mart）中分离得到的一种新型的季铵盐类吲哚生物碱，含有一个不常见的氮鎓杂三环[4.3.3.0^1,5]十一烷的结构片断。从苄基保护的色胺出发，经过Michael加成、Pictet-Spengler反应以及Dickmann酯缩合等反应合成了四环羰基化合物。从这个中间体出发经过两次Aldol反应构建了其基本骨架，相对构型通过双键的立体选择性氢化加以控制。最终在钠液氨条件下脱除苄基保护得到成环前体，随后的磺酰化，分子内环化完成了Subincanadine C的全合成，但是合成得到的季铵盐和分离得到的样品图谱有出入，有待单晶结构确认15和16位的相对构型。生物碱（S）-nicotine有很强的的药理活性，并在自然界大量存在。氟的引入成为修饰化合物生物活性的一种手段，我们希望通过合成一系列刚性构象的含氟的尼古丁类似物，从而获得治疗神经系统类疾病药物的先导化合物。第三部分工作主要通过亲核氟化反应以及利用含氟合成子3-溴-3，3-二氟丙烯和一溴二氟乙酸乙酯通过适当的反应途径将氟原子引入到目标分子中合成了一系列含氟尼古丁类似物。更多还原

【Abstract】 This dissertation mainly focuses on synthetic studies of nakadomarin A,subincanadine C, and fluorinated conformationally restricted nicotine analogues.(-)-Nakadomarin A is a novel manzamine-related alkaloid isolated from a marinesponge Amphimedon sp. by Kobayashi et al in 1997 and consists of an unprecedented8/5/5/5/15/6 ring system, which contains a furan ring. Biological assays indicate thatit is cytotoxic against murine lymphoma L1210 cells, inhibits CDK4, and showsantimicrobial activity. Our synthesis features the construction of the strained ABCDcore involving key transformations such as stepwise reductive amination, Sonogashiracoupling, and a platinum(II)-catalyzed cascade reaction sequence. The 8- and15-membered azacycles (i.e., E and F rings) were both obtained by ring-closingmetathesis (RCM). However, for the formation of the 15-membered azacycle viaRCM, a mixture of two geometrical isomers (Z/E = ca. 2:3, by NMR), with thedesired product as the minor one. Further efforts directed to solve the probleminvolves the attempted formation of the 15-membered azacycle by intermolecularWittig olefination (to synthesize the Z-cycloalkene in higher stereoselectivity)followed by intramolecular SN2 reaction or reductive amination, which is still ongoingin our laboratory.Subincanadines C was isolated by Kobayashi et al in 2002 as a novel quaternaryindole alkaloid from a Brazilian medicinal plant, Aspidosperma subincanum. Thiscompound possesses an unprecedented 1-azoniatricyclo[4.3.3.0～（1,5）]undecaneframework. The tetracyclic ketone was constructed from 1-benzyltryptamine featuringMichael addition, Pictet-Spengler cyclization, and Dieckmann condensation. In orderto form the E ring, further manipulations on the key ketone intermediate included theutilization of Aldol condensation (twice) and stereoselective hydrogenation to attachan appropriate side chain. Finally, subincanadine C was successfully obtained throughreductive debenzylation followed by a sequential sulfonation/cyclization (i.e.,intramolecular ammonium formation) process. However, our spectral data are not infull consistence with those reported for this natural product in the literature. Furtherexperimental evidence (e.g., X-ray crystallographic data) will be required to provideinsight into the relative stereochemistry of C-15 and C-16. (S)-Nicotine, an alkaloid present together with a number of minor alkaloids intobacco and a wide variety of other plants, has various biological activities. On theother hand, introduction of fluorine atoms into organic compounds has beenextensively used to modify the biological activities. We have been engaged indesigning and synthesizing fluorinated nicotine analogues with rigid conformations toseek promising lead compounds for the treatment of central nervous system (CNS)disorders. Two strategies for the incorporation of fluorine atoms into nicotineanalogues have been investigated and they are: (i) application of appropriatefluorine-containing building blocks such as 3-bromo-3,3-difluoropropene and ethylbromodifluoroacetate, and (ii) direct fluorination of alcohols or ketones to affordfluorine-substituted nicotine analogues.更多还原