Study On The Highly Efficient Stereoselective Tandem Reactions Of Meldrum's Acid Olefins And Benzyl Halides For The Synthese Of ?-butyrolactones

This thesis mainly studies the stereoselective cyclopropanation reaction of Meldrum's acid olefins and polysubstituted benzyl halides,and the stereo specific thermal decarboxylative Cloke-Wilson rearrangement reaction of spirocyclopropyl Meldrum's acid.A series of multi-substituted y-butyrolactones compounds were synthesized.The main research contents are as follows:1?Organic base promotes diastereoselective spirocyclopropanation of Meldrum's acid olefins with polysubstituted benzyl halides to synthesize spirocyclopropyl Meldrum's acidsMeldrum's acid derivatives are a class of pharmacologically and physiologically active compounds that have been widely used in the treatment of various diseases.The cyclopropane skeleton is a unique cyclic scaffold,widely present in natural products and synthetic compounds,and also a useful intermediate with reactive properties in organic synthesis.The fusion of these two important properties makes the spirocyclic Meldrum's acids of considerable importance in the field of pharmacological applications.This part is mainly to explore the organic base promoted spirocyclopropanation of Meldrum's acid olefins with polysubstituted benzyl halides.Because our main purpose is to synthesize y-butyrolactones compounds,only 4 representative spirocyclopropanes compounds were separated and purified.Other spirocyclopropane compounds were directly studied for the synthesis of ?-butyrolactones compounds.#122?Synthesis of ?-butyrolactones compounds by Cloke-Wilson rearrangement reactions of spirocyclopropyl Meldrum's acidsButyrolactones are widely found in numerous natural and synthetic products with diverse biological activities and odorant properties.Especially,in medicinal chemistry,it has versatile pharmacological properties,therefore it is very important to explore efficient methods to synthesize this compound.This part is mainly to explore the Cloke-Wilson rearrangement reactions of spirocyclopropyl Meldrum's acids.A series of 26 y-butyrolactones were synthesized with moderate to good overall yields from 46%to 96%and excellent diastereoselectivities.(?)...