Construction Of 6/6-Bicyclic Lactones Via Microwave-Assisted Tandem Reactions And Synthesis Of Isoindolin-1-ones

As one of the most important organic reactions, Diels-Alder reaction is usually used to produce complicated polycyclic compounds. This thesis focuses on the construction of 6/6-bicyclic lactones via microwave-assisted tandem wittig-intramolecular Diels-Alder (IMDA) reactions and the synthesis of isoindolin-1-ones in cytochalasin Z8.Chapter 1 is a review of intramolecular Diels-Alder reactions. We introduce the stetrochemistry of 5/6-bicyclic lactones,6/6-bicyclic lactones and bicyclic lactams. Then, it is presented many efficient lewis acid catalysts for IMDA reactions of ester-tethered substrates to construct 6/6-bicyclic lactones. Also, some applications of MDA reactions in total synthesis of natural products which include 6/6-bicyclic lactone structures are enumerated.Chapter 2 briefly introduces microwave assisted organic synthesis and the known "one-pot" Wittig reaction. Then, it is expounded that the preparation of ester-tethered 1,7,9-trienes, the construction of 6/6-bicyclic lactones respectively via microwave-assited IMDA reactions and microwave-assisted tandem Wittig-IMDA reactions. The isomers from tandem reaction by the microwave assisted IMDA reactions are analyzed, and the stereochemistry of the isomers is determined by the X-ray results and related documents.Chapter 3 concerns the natural product cytochalasins which include isoindolin-1-ones. The retrosynthetic analysis of cytochalasin Z8 is presented, and the synthesis of the skeleton of isoindolin-1-ones is accomplished. And we also discover one oxygen-hetero-Diels-Alder reaction. The experimental section, the characterization data for the key intermediates and the final product, the cited references, the copies of original 1H and 13C NMR spectra and the data of X-ray single crystal structural analysis are found at the end of the thesis.