Synthesis of strigolactone (±)-gr24 and 4-substituted (±)-gr24

Abstract

The invention discloses a synthetic method of strigolactone (+ / -)-GR24 and 4-substituted (+ / -)-GR24. The method comprises the following steps: benzoic acid which is used as a raw material reacts with dibromomethane to obtain an intermediate as shown in the formula I; the intermediate I undergoes diisobutylaluminium hydride reduction to obtain an intermediate as shown in the formula II; the intermediate II and (2-carboxyethyl)triphenylphosphonium bromide undergo coupling under the action of alkali so as to obtain an intermediate as shown in the formula III; the intermediate III reacts with Dess-Martin periodinane to obtain an intermediate as shown in the formula IV; the intermediate IV undergoes cyclization under the action of an acid catalyst or reacts with a nucleophilic reagent so as to obtain ABC tricyclic lactone, namely an intermediate as shown in the formula V; the intermediate V and ethyl formate undergo a formylation reaction to obtain an intermediate VI; and the intermediate VI and bromobutenolide undergo coupling so as to obtain (+ / -)-GR24 and 4-substituted (+ / -)-GR24. The raw materials used in the synthetic method are cheap and easily available; the operation is simple; reaction conditions are mild; safety is high; the catalyst used in the invention is environment-friendly; tricyclic lactone can be constructed by one-step tandem cyclizaiton reaction; the reaction route is short; and overall yield is high. Thus, total cost is greatly reduced. The synthetic method meets requirements of mass synthesis.

Description

technical field [0001] The invention belongs to the technical field of strigolactone synthesis, in particular to a synthesis method of strigolactone (±)-GR24 and 4-substituted (±)-GR24. Background technique [0002] Strigolactones are a class of sesquiterpenoids discovered in the study of plant root exudates. It is a general term for some natural strigyl alcohol compounds and synthetic analogues. (±)-GR24(3-(4-Methyl-5-oxo-2,5-dihydrofuran-2-oxymethyl)-3,3a,4,8b-tetrahydro-indeno(1,2 -b) Furan-2-one, referred to as GR24) is the first artificially synthesized strigolactone, which is composed of hexapentapentatricyclic lactone coupled with bromobutenoic acid lactone through an enol ether bond. linked together. Studies have shown that (±)-GR24 and 4-substituted (±)-GR24 have a variety of biological activities, and have good application prospects in promoting plant germination, regulating plant branching, and inhibiting breast cancer cell proliferation. The structures of (±)...

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Problems solved by technology

The advantage of this method is that the raw materials are cheap and easy to get, but the disadvantage is that the total reaction steps are too long, the total yield is low, and more expensive heavy metal catalysts are used, and the amount of catalyst used in the ring-closing reaction is large

The disadvantage of this method is that the raw materials are relatively expensive, and the use of toxic organotin reagents and heavy metal catalysts in the reaction will cause great pollution to the environment, and there are "head-to-tail" addition by-products in the ring-closing reaction. low yield

This method reported the synthesis of (±)-4-OH-GR24 for the first time. The disadvantage is that the raw material starts from a special ABC tricyclic lactone, and a heavy metal catalyst is used in the synthesis.

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