Method for synthesizing natural sesquiterpene Crepis virens extract (8-Epigrosheimin)

A sesquiterpene lactone and synthetic method technology, applied in the field of chemical synthesis, can solve the problems of large side effects, carcinogenicity, poor effect, etc., and achieve the effect of simple operation and high yield

CN101481367AInactive Publication Date: 2009-07-15NANKAI UNIV
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2009-07-15
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to a synthetic method of natural sesquiterpene lactone crepin (8-Epigrosheimin) with anti-ameba protozoon activity. The method comprises the following steps: synthesizing 2-methyl-3-methoxyl methyl-5-isopropenyl-cyclopentanealdehyde which is obtained by synthesizing carvone with 3-bromomethyl-5H-furan-2-one which is obtained by synthesizing by 1,4-butyrolactone under an action of zinc to obtain an intermediate A; performing alkali ring opening followed by acidification to obtain an intermediate B; performing Michael addition on thiophenol to obtain an intermediate C; oxidizing with Swern, and cyclizing with the catalysis of Lewis acid to obtain an intermediate D; regenerating double bonds by oxidization and thermal elimination to obtain an intermediate E; and performing deprotection and selective oxidation to obtain a target compound. The method is characterized by conveniently obtaining the optically pure target compound by using only one protective group without any other chiral reagents, catalyst or noble metal, and realizing first total synthesis of the compound. The material is easily obtained, the operation is simple, and the yield is high. The compound is expected to have great treatment application as a specific drug for treating amebic liver abscess.
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Description

technical field

[0001] The present invention relates to the chemical synthesis of active substances of sesquiterpene lactones in natural plants, in particular a method for the total synthesis of natural sesquiterpene lactones (8-Epigrosheimin) with anti-amoeba activity, Specifically, starting from readily available raw materials in the market, stereospecific and enantioselective synthesis is used to obtain optically pure natural products. The compound can be used as a bactericidal and anti-amoeba drug or its precursor. Background technique

[0002] Amoeba can parasitize in human or animal tissue. The protozoan mostly parasitizes the intestines and livers of humans and animals, and rarely parasitizes the lungs, brain, and spleen, and invades the body in the form of trophozoites, thereby causing amoebic dysentery (expressed as acute and chronic amoebic dysentery) ) or extraintestinal infection (ie amebic liver abscess). Amebic enteropathy can cause many serious complication...

Examples

Embodiment

[0028] The synthesis of key intermediate 2-methyl-3-methoxymethyl-5-isopropenyl-cyclopentanecarbaldehyde (5-Isopropenyl-3-methoxymethoxy-2-methyl-cyclopentanecarbaldehyde) of the present invention refers to literature method to synthesize, the yield is 50%. (Lee E, Yoon C H. Stereoselective favorskii rearrangement of carvone chlorohydrin: Expedient synthesis of (+)-dihydrone petalactone and (+)-iridomyrmecin. JChem S, Chem Commun, 1994: 479~481)

[0029] 1. Synthesis of intermediate 3-bromomethyl-5H-furan-2-one:

[0030]

[0031] Synthesis of Compound 1a

[0032]Add 42g of 1,4-butyrolactone and 5.7g of red phosphorus to a 500mL four-neck flask (thermometer, reflux condenser, dropping funnel, electromagnetic stirrer), stir for 0.5h, then add 28mL of liquid bromine under an ice bath, and dropwise Afterwards, the temperature rose to 70°C, and 28 mL of Br2 was added dropwise again. After the drop, the temperature rose to 80°C, reacted for 3 hours, cooled, blown in air, and to...