Synthetic method of 6.6-dimethyl-3-oxadicyclo[3.1.0] hexane-2.4-dione

The invention discloses a synthetic method of 6.6-dimethyl-3-oxadicyclo[3.1.0] hexane-2.4-dione, characterized by: using first ethyl chrysanthemate as a raw material, adding a phase transfer catalyst in water, carrying out oxidation of potassium permanganate and then carrying out reduction through sodium pyrosulfite in an acid medium to generate 3.3-dimethyl-1.2-cyclopropane dicarboxylic acid, and in dehydrating in acetic anhydride to obtain the closed-loop generation of 6.6-dimethyl-3-oxadicyclo[3.1.0] hexane-2.4-dione. According to the invention, the invention has the advantage of simple operation; after adding the phase transfer catalyst, compared with a process in the prior art, the amount of the solvent (the solvent used in the prior art is acetone.)is greatly saved, and the cost is greatly reduced; after using sodium pyrosulfite for reduction, the amount of acids is greatly reduced, the treatment of environment and three wastes is reduced, and simultaneously the yield is increased.