Studies on the Development of Practical Electroorganic %reactions Associated with Biological Processes

利用天然生物质中的手性结构单元合成具有生物活性的化合物是当前的研究热点。本研究项目涉及（A）手性生物质电化学转化为多功能手性合成子及其合成应用和（B）通过电化学方法将生物化学产生的青霉素衍生物转化为有价值的头孢菌素化合物及其应用。在研究项目（A）中，我们开发了基于有机电反应的有效官能团制备方法，即硒化-脱硒化序列，（2）环氧乙烷的选择性环重排，（3）四氧化钌介导的醇氧化，（4）卤素介导的呋喃开环等。这些方法的合成效用显示在有用的生物活性化合物的合成中，例如从乙酸脱氢苯酯合成卡拉哈纳烯酮和从（+）-3-<$烯合成胆甾酸等。在第二个研究计划（B）中，我们成功地对氮杂环丁烷酮的异戊二烯基部分进行了选择性烯式氯化。该方法已推广应用于多种头孢菌素类似物的合成。还研究了3 '-氯头孢菌素转化为相应的3-亚甲基头孢菌素。

Use of chiral building blocks easily accessible from natural bio-mass is of current topics in the synthesis of bio-active compounds. This research project concerns with (A) electrochemical transformations of chiral bio-mass into versatile chiral synthons and their synthetic applications and (B) conversion of biochemically produced penicillin derivatives into the valuable cephalosporin compounds by electrochemical means and their applications. In the research project (A), we developed an efficient functional group preparing methods based on electoorganic reactions, i.e. selenation-deselenation sequence, (2) selective ring rearrangement of oxiranes, (3) ruthenium tetraoxide mediated oxidation of alcohols, (4) halogen mediated ring cleavage of furans, and others. Synthetic utilities of these methodologies are shown in the synthesis of useful bio-active compounds such as karahanaenone from dehydrolynalilyl acetate and chrysanthemic acids from (+)-3-carene, and others. In second research program (B), we have succeeded in the selective ene-type chlorination of prenyl moiety of azetidinones. The procedure has been extended in the practial synthesis of a variety of cepharosporin analogues. Conversion of 3'-chlorocephalosporins into the corresponding 3-methylenecephams is also investigated.