1) Results: Two mono-hydroxy intermediates were produced during the diketone reduction process and its reverse reaction, which were separated and structurally confirmed.

2) Novel synthetic methods for alkyl methyl ketone, symmetric diketone , long-chain diketone and macrocyclic ketone were provided.

3) The long-chain diketone described above was applied to the synthesis of macrocyclic ketone and a new method for macrocyclic ketone was reported.

4) Their infrared spectra indicate that one had the diketone stuctureand the other, the cyclol structure.

5) Novel substituted 2,4-thiazolidine diketone derivatives, method for preparation thereof and pharmaceutical compositions containing the same.

6) Methods: Referring to dienogest's construction features, we reconstructed anordrin be- ginning with diketone.

7) This invention relates to a method for preparing amide diketone acids and their pharmaceutical application.

8) The addition-hydrolysis reaction of bisbenzimidazolium salt with Grignard reagent was reported and a novel synthetic method for symmetric long-chain diketone was provided.