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The Claisen Rearrangement Using Carbohydrate Derivatives and Its Application to Natural Product Synthesis

碳水化合物衍生物的克莱森重排及其在天然产物合成中的应用

基本信息

批准号：
01550680
负责人：
TADANO Kin-ichi
金额：
$ 1.09万
依托单位：
Keio University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

项目摘要

1. The ortho-ester Claisen rearrangement (Johnson-Claisen rearrangement) is one of the highly stereoselective carbon-carbon bond forming reaction in current organic synthesis. Our interest is a pursuit of the highly stereoselective Claisen rearrangement reaction applied to carbohydrate-derived substrates for access to versatile chirons. The ortho ester Claisen rearrangement of Z-isomer of 3, 5, 6-trideoxy- 1, 2-OMICRON-isopropylidene-3-C-methyl-alphaーD-ribo-hept-5-eno-1, 4-furanose with triethyl orthoacetate proceeded highly stereoselectively to form the major rearrangement product with (S)- newly introduced asymmetric center (9 to 1 diastereoselectivity). This product includes a 1, 3-dimethylー2, 4-diol substructure, and is expected to be a useful building block for such the macrolide synthesis (J. Carbohydrate Chem., in press).2. The utility of the rearrangement product has been embodied through total synthesis of natural products such as (+)-asteltoxin. The subject of this Grantーinーaid is the total synthesis of (-)-acetomycin, an antimicrobial and antitumor agent. The starting material for the total synthesis was the major product obtained by the Claisen rearrangement of D-glucose derived allylic alcohol at C-3 and triethyl orthopropionate. This first total synthesis of (-)-acetomycin established its absolute configuration. In the course of the total synthesis, one of the stereocongeners of the antibiotic, (+)-5-epiーacetomycin was also synthesized. From the minor product of the Claisen rearrangement, the other two stereocongeners, 4-epi-, and 4, 5-di-epi-acetomycin were synthesized by analogous reaction sequence adopted to the (-)-acetomycin synthesis.

1. 邻位酯Claisen重排（Johnson-Claisen重排）是目前有机合成中高度立体选择性的碳-碳键形成反应之一。我们的兴趣是追求高度立体选择性的Claisen重排反应应用于碳水化合物衍生的底物，以获得多功能chirons。3,5,6 -三脱氧- 1,2 - omicron -异丙基-3- c -甲基- α - d -核糖-庚-5-烯- 1,4 -呋喃糖z -异构体与正乙酸三乙酯的邻位酯Claisen重排进行了高度立体选择性，形成了具有(S)-新引入的不对称中心的主要重排产物（9对1非对映选择性）。该产物含有1,3 -二甲基2,4 -二醇亚结构，有望成为此类大环内酯合成的有用构建块（J.碳水化合物化学）。（待定）。通过(+)-星形毒素等天然产物的全合成，体现了重排产物的实用性。这项资助的主题是抗菌和抗肿瘤药物(-)-乙酰霉素的全合成。全合成的起始原料是d -葡萄糖衍生的烯丙醇在C-3和正丙酸三乙酯的Claisen重排得到的主要产物。这是(-)-乙酰霉素的首次全合成，确定了它的绝对构型。在全合成过程中，还合成了该抗生素的一个立体同源物(+)-5-乙醯乙霉素。从clisen重排的次要产物出发，采用与(-)-乙酰霉素合成相似的反应顺序，合成了另外两个立体同源物4-epi-和4,5 -二epi-乙酰霉素。