Preparation method of neohesperidin dihydrochalcone

The invention discloses a preparation method of neohesperidin dihydrochalcone. The method comprises the following steps: (1) carbonyl protection: dissolving the neohesperidin in an organic solvent or organic solvent aqueous solution, adding trimethyl orthoformate or triethyl orthoformate and ketal catalyst to perform the ketal reaction, reducing pressure and concentrating, cooling and crystallizing, filtering and drying to obtain a compound I; (2) hydrolysis reaction: dissolving the compound I in an aqueous alkali of the compound II; (3) hydrogenation reaction: adding the hydrogenation catalyst, introducing nitrogen to protect, and introducing the hydrogen to perform the hydrogenation reaction, filtering to obtain the aqueous alkali of the compound III; (4) acidification and crystallization: regulating pH value, cooling and crystallizing, filtering and drying to obtain the neohesperidin dihydrochalcone. The yield of the neohesperidin dihydrochalcone prepared through the method disclosed by the invention could