Studies On The Synthesis, Bioactivity Evaluation Of Spirotetramat Derivatives And The Synthesis Of Spirocyclic Ketal Intermediate

Spirocyclic tetronic acid compounds have been attracting the interest of scientists continuously due to their original structures, novel mode of action, and excellent biological activity levels. For instance, the recently commercialized insecticides spirodiclofen, spiromesifen and spirotetramat, belonging to the new chemical classes spirocyclic tetronic acid have been developed by Bayer CropScience AG, respectively. Spirotetramat has a unique mode of action, which is considered a novel two-way ambimobile systemic insecticide, and it has been worldwide used on a great variety of crops and it has shown outstanding performance against sucking pests. Therefore, as an excellent lead compound, the structure of these compounds is attracting the attention of many scientists.This article analysed systematically the status and trends of the pesticides development firstly, and introduced the methods of the new pesticides development, and demonstrated the importance and urgency of the new pesticide development. And at the same time, the importance of spirocyclic tetronic acids insecticides and acaricides were analysed and concluded. It provides the basis for the new pesticide development.Aimed at the discovery and development of more effective, broad-spectrum, bioactive, no cross-resistance novel compounds, on the basis of our previous research and spirotetramat metabolites, according to substructure linking method, commercialized pesticide Spiroteramat was modified by structural transformation and optimize design to synthesis three series of aldehyde moiety, spirocyclic ketal and oxime ether substituted derivatives. Their structures were confirmed by1H NMR and MS even X-ray diffraction. All the target compounds were measured for its bioactivity in the help of Hunan Bioassay Center Department. The results showed that the compound3g、3h、5b、5d、5m and7a show excellent inhibition activity against aphid and the compounds3h、5b and7a show excellent inhibition activity against spider mites at the concentration of100mg/L. However, all compounds displayed lower bioactivity or no bioactivity against armyworm at test concentration of100mg/1. At the same time, we studied the relationship of the structure and biological activities in order to design more active compounds in future. And the log P value of these compounds were calculated for the preliminary study of the impact on the biological activity. It provides a new methods for future research and molecular design. On the basis of a literature review, an economic, simple operational and environmental friendly synthetic process of spirocyclic ketal intermediate was developed. In this paper,1,4-Dioxa-spiro[4.5]decan-8-one was used as raw material via Bucherer-Bergs reaction, alkaline hydrolysis and esterification, amidation reaction with2,5-dimethyl phenylethyl chloride, Dieckmann condesation to form a ring, and finally to get the target compound11-(2,5-Dimethyl-phenyl)-12-hydroxy-1,4-dioxa-9-aza-dispiro[4.2.4.2]tetradec-11-en-10-one(S-6). The mechanisms of eaeh reaction were also discussed, and factors affeting the reactions such as solvents, catalysts, temperature, molar ratio have been studied and the optimum process was acquired. The experiment proved that this route is feasible, while avoiding patent infringement, and provided a large number of compounds for subsequent further study and screening more efficient insecticidal active compound structure and screening more efficient insecticidal active compound structure.