Preparation of Key-Intermediates for the Synthesis of Clerodane Natural Products

氯罗丹天然产物合成关键中间体的制备

• 批准号: 08680625
• 负责人: KATO Michiharu
• 金额: $ 1.6万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08680625/
• 关键词: Clerodane; Biological Activity; Natural Product; Asymmetric Synthesis; Key-Intermediate; Diterpene; Conjugate Addition; (-)-コラベン酸; 分子内エン反応; (+)-ノピノン; 全合成; 共役付加

Clerodanes constitute a large class of diterpenoids, and display unique biological activities among which the insect antifeedant represented by clerodin is well known. The most important characteristic in this class is four contiguously arranged chiral centers ; C (5) -C (10) -C (9) -C (8), in a molecule.To synthesize these clerodane natural products, we have accomplished stereocontrolled preparation of two kinds of key-intermediates ; (3S,4R,4aS,8S,8aR) -7,7-ethylenedioxy-3,4,8,8a-tetramethyl-4-vinyl-3,4,4a, 5,6,7,8,8a-octahydronaphthalen-2 (1H) -one 1 and (3S,4R,4aS,8aR) -3,4,8,8a-tetramethyl-4-vinyl-3,4,4a, 5,6,8a-hexahydronaphthalen-2 (1H) -one2, which possess correctly arranged four chiral centers, necessary for the enantioselective synthesis of neo-trans-clerodanes.The acetal and ketone functions would serve as a clue for construction of oxygenated A and B rings. In addition, as a vinyl group is equivalent to the synthetically versatile ethanal moiety, installment of this function in 1 and 2 could be useful for construction of a six-carbon substituent at the C(9) position in the clerodane-synthesis.

克罗烷类化合物是一类具有独特生物活性的二萜类化合物，其中以克罗丁为代表的昆虫拒食剂最为人们所熟知。这类化合物最重要的特征是在一个分子中有四个连续排列的手性中心C（5）-C（10）-C（9）-C（8）。（3S，4 R，4aS，8 S，8aR）-7，7-亚乙二氧基-3，4，8，8a-四甲基-4-乙烯基-3，4，4a，5，6，7，8，8a-八氢萘-2（1H）-酮1和（3S，4 R，4aS，8aR）-3，4，8，8a-四甲基-4-乙烯基-3，4，4a，5，6，8a-六氢萘-2（1H）-酮2，其具有正确排列的四个手性中心，缩醛和酮的功能将作为一个线索，为建设含氧的A和B环的对映选择性合成新反式克罗烷。此外，由于乙烯基相当于合成通用的乙醛部分，在1和2中安装该官能团可用于在氯罗丹合成中在C（9）位构建六碳取代基。

项目成果

Michiharu Kato, Hiroshi Kosugi, Ariko Kodaira, Hisahiro Hagiwara, and Bernhard Vogler: "Stereocontrolled Synthesis of the Key Intermediate for the Enantioselective Synthesis of Clerodane Natural Products" Tetrahedron Letters. 38-39. 6845-6848 (1997)

Michiharu Kato、Hiroshi Kosugi、Ariko Kodaira、Hisahiro Hagiwara 和 Bernhard Vogler：“用于 Clerodane 天然产物对映选择性合成的关键中间体的立体控制合成”四面体字母。

Michiharu Kato: "Stereocontrolled Synthesis of the Key Intermediate for the Enantioselective Synthesis of Clerodane Natural Product" Tetrahedron Letters. 38・39. 6845-6848 (1997)

加藤道晴：“对映选择性合成 Clerodane 天然产物的关键中间体的立体控制合成”Tetrahedron Letters 38・39 (1997)。