The invention discloses a preparation method of a
vitamin A midbody,namely 3, 7-dimethyl-9-(2', 6', 6'-trimethyl-1-
cyclohexene) base-2,4,7-triene-1,6-
diol-1-acetic ester, and the preparation method comprises the steps of filtering a culture solution obtained through
fermentation cultivation of
aspergillus oryzae WZ007, treating dry
thallus obtained by
drying filter cakes as a catalyst, treating 3, 7-dimethyl-9-(2', 6', 6'-trimethyl-1-
cyclohexene) base-2,4,7-triene-1,6-
diol as a reaction substrate, treating an
organic solvent solution of an acylating agent as a reaction medium, conducting reaction under the conditions of 30-50 DEG C and 200 rpm, after the reaction is ended, filtering reaction liquid, recycling the filter cakes and the catalyst, wherein filtrate is mixed liquor containing the
vitamin A midbody, conducting separation and purification on the mixed liquor, and obtaining the
vitamin A midbody. According to the preparation method of the vitamin A midbody, the area selection rate of used
enzyme reaches 99.5%, the reaction conversion rate is as high as 100%, the catalyst can be recycled, the downstream separation is simple,
energy consumption is low, production cost is greatly lowered, environmental
pollution is little, and the preparation method is suitable for industrial production.