Study On The Synthesis Of Natural Products Calyxins And Technics Of A High-efficient Pesticide Indoxacard

This thesis mainly contains three parts, which include tandem Prins cyclization(review), study on the total synthesis of natural products Calyxins and the synthetical technics of a high-efficient pesticide indoxacard.Part I: Tandem Prins cyclization reactionReaction categories, catalyst system, reaction mechanism of the tandem Prins cyclization have been introduced in the review, which also included some successful applications in the construction of a number of complex natural products, especially substituted tetrahydropyran derivatives.Part II: Study on the total synthesis of CalyxinsThis chapter was the synthesis of compounds 1,7-diarylheptanoids 34 and chalcone 30 which can link to the Calyxin B.The starting material was 4-hydroxylbenzaldehye. Via the main steps of Knoevenagel condensation, catalytic hydrogenation, esterification, reduction, oxidation by PCC and Aldol condention, we obtained compounds 34 successfully. The key step was the Aldol condention in the presence of LDA.The starting material was phloroglucinol. Through Hosech reaction, phenolic hydroxyl protection, selective methoxide, Aldol reaction and deprotection, compound 30 was obtained.The link of fragment 34 and fragment 30 were tried through Friedel-Crafts reaction, however, the expected results were not obtained. Based on several literatures, the construction mentioned above can be accomplished by the tandem Prins/Friedel-Crafts reaction.Part III: Study on the synthetical technics of a high-efficient pesticide indoxacardThe protocol shows some advantages in terms of its simple operation, easily availability, and cheap cost(comparing with the relative patents).Finally, compound indoxacard was gained with satisfactory yield via the main steps of Friedel-Crafts reaction, oxidation by peracetic acid, esterification, Dieckmann condention, asymmetric oxidation, cyclization, catalytic hydrogenation and condention using 4-chlorophenylacetic acid as the starting material.