The Synthesis Of Derivations Of 5-oxo-4H-5,6,7,8-tetrahydrobenzopyran With Microwave Assisted

This thesis describes the synthesis of the derivations of 5-oxo -4H- 5,6,7,8-tetrahydrobenzopyran with the assistance of microwave. Materials such as aromatic aldehydes treated with three main steps gave the object products, which are microwave assisted Wittig reaction, microwave assisted one-pot reaction with Michael Addition and Claisen Condensasion followed with hydrolyzation then decarboxylation, and microwave assisted one-pot reaction with Michael Addition and cyclisation. The yield is much higher but the reaction time became much shorter than the traditional method.At the first step of the synthesis, Materials such as aromatic aldehydes are used to prepare 4-R-3-buten-2-ones with different substisuents. Microwave assisted Wittig reaction made the synthesis of 4-R-3-buten-2-ones, which could not exist in alkali substance because of their high activity, possible and also notably shorten the reaction time of some reaction with very long reaction time.derivations of 1,3-cyclohexanedion are very important organic intermediates and are also very important to the synthesis described in this thesis. 4-R-3-buten-2-ones prepared from the first step gave 5-R-1,3-cyclohexanedions through the microwave assisted one-pot reaction with Michael Addition and Claisen Condensasion followed with hydrolyzation then decarboxylation.5-R-1,3-cyclohexanedions and chalcones reacted with each other through microwave assisted one-pot reaction with Nucleophilic Substitution and cyclisation with the catalysis of ZnCl₂ gave the object products, derivations of 5-oxo-4H-5,6,7,8-tetrahydrobenzopyran.