Method for producing all trans-teprenone

The invention provides a method for producing all trans-teprenone, comprising the following steps of: (1) synthesizing teprenone through Carroll reaction to obtain a teprenone crude product; (2) pickling the teprenone crude product by the use of hexane and sulfuric acid, carrying out alkali washing by the use of a sodium bicarbonate solution, washing to neutral, and removing an emulsification layer and a water layer to obtain mixed teprenone after washing; (3) adding hexane for dilution, standing at minus 15-minus 20 DEG C for 20-24 hours, cooling to minus 30-minus 60 DEG C, and crystallizing all trans-teprenone; and (4) centrifuging the crystals at minus 20-minus 40 DEG C to obtain the all trans-teprenone having a purity of greater than 99%. Through an ultralow temperature separation method and an apparatus, all trans-teprenone having a purity of greater than 99% is obtained from a cis-trans isomer which is hard to separate under the condition of high temperature and other purities which can be separated by a rectification means. In addition, cis and other impurities do not exceed 1%.