Method for preparing isosteviol through catalytic hydrolysis of stevioside by chlorinated aromatic sulfonic resin

The invention provides a method for preparing isosteviol through catalytic hydrolysis of stevioside by chlorinated aromatic sulfonic resin, which belongs to the technical field of organic synthesis of organic compounds. According to the invention, a chlorinated aromatic sulfonic ion exchange macroporous resin packed bed is used for continuous catalytic hydrolysis of stevioside so as to prepare isosteviol, and a step-by-step cooling and circulation manner is adopted to remove products in time and to accelerate reaction. The method provided by the invention has the advantages of high yield, simple operation, environment friendliness, good stability performance of the catalyst, etc. The strong chlorinated aromatic sulfonic ion exchange macroporous resin can maintain 97% of catalytic activity after repeatedly used 10 times. Yield of isosteviol can reach more than 95%, and purity of isosteviol is more than 98% after simple recrystallization.