Preparation method of 24-epibrassinolide

Abstract

The invention relates to a preparation method of a plant growth regulator, in particular to a preparation method of 24-epibrassinolide, which belongs to the chemical field, and comprises the following steps that: 1. starting from ergosterol 1, an intermediate body 3 is prepared through two reactions, i.e. methyl sulfonyl and hydrolysis according to a traditional synthesis process; 2. the intermediate body 3 is oxidized by a novel oxidation system osmium tetroxide / inter-chloro benzoic acid peroxide to prepare an intermediate body 4; and 3. the intermediate body 4 is finally converted into the 24-epibrassinolide 8 through four reactions, i.e. reduction, rearrangement, dihydroxylation and lactonization according to the traditional synthesis process. Compared with the traditional oxidation system chromium trioxide / pyridine used in the oxidization of the intermediate body 3 into the intermediate body 4, the novel oxidation system used by the invention has the advantages of convenient operation and little pollution, and is more applicable to industrial production.

Description

Technical field The invention relates to a preparation method of a plant growth regulator, especially a preparation method of 24-epibrassinolide. It belongs to the field of chemistry. Background technique In 1979, Crove and others of the Research Institute of the United States Department of Agriculture extracted a compound with a steroidal skeleton structure from rape pollen, which was later named Brassinolide (Brassinolide, also called brassinolide) (MD Grove, GFSpencer, WK Rohwedder, N. Mandava, JF Worley, JD Warthen, Jr., GL Steffens, JLFlippen-Anderson, and JCCook, Jr., Nature (London), 1979, 281, 216). It has a very strong physiological activity, at very low concentrations (10 -9 G / L) shows a significant function of promoting plant growth and development. So far, people have isolated nearly 60 kinds of brassinolide from plants. Among them, brassinolide, 24-epibrassinolide and 28-homobrassinolide are the three most active. 24-Epibrassinolide is the first sterol compound...

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Problems solved by technology

However, when we repeated this experiment, we found that the reaction situation was not ideal, the impurity content was high, and the experimental operation was very complicated

It can be seen that the current reports on the laboratory synthesis method of 24-epibrasinolide still have many reaction steps, relatively complicated operations, and the toxicity of the reagents used can easily cause environmental pollution. It is difficult to meet the market-oriented large-scale production Require

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