The invention relates to a synthesis method of low-cost environment-friendly
dioscorea element I. The synthesis method comprises the following steps: by taking 3, 5-dimethoxybenzyl
alcohol as a
raw material, brominating, reacting with triethyl phosphite and 4-benzyloxy-3-methoxybenzaldehyde to generate 3, 4 ', 5-trimethoxy-3'-benzyloxy stilbene, carrying out
ultraviolet cyclization reaction, reacting with
palladium-carbon,
palladium-carbon,
palladium-carbon, palladium-carbon, palladium-carbon, palladium-carbon, palladium-carbon, palladium-carbon, palladium-carbon, palladium-carbon, palladium-carbon, palladium-carbon, palladium-carbon, palladium-carbon, palladium-carbon, palladium-carbon, palladium-carbon, palladium-carbon and debenzylating with
hydrogen to obtain the Chinese yam element I. The
potassium iodide is used as the catalyst in the
ultraviolet lamp
irradiation catalytic ring closing reaction, the pure water is used as the detergent, compared with the method adopting
iodine as the catalyst and adopting a
sodium thiosulfate aqueous solution as the detergent, the product yield of the compound 33-4 is 75%, the yield of the compound 33-5 is 16.6%, the purity is 98.7%, and the method has the advantages of low cost, high yield, few impurities and the like.