Synthesis Of Some Intermediates In The Synthesis Of Natural Products GLZYZJ - 1

Coumarins of natural products are kinds of compounds with important biological activity that based on Benzo-α-pyrone nucleus.According to biogenesis hypotheses,these compounds are divided into four categories.On total synthesis of such compounds and biomimetic transformation,it has attracted widespread attention of synthetic chemists.This thesis mainly focuses on the following two aspects:1)a brief introduction of the separation、biogenic hypothesis、structural classification activity of Coumarins of natural products and total synthesis of some typical natural products.2) details of the synthetic study about chiral dihydrocoumarin derivative CLZYZJ-1(with a 90% inhibition) that is separated by Kunming institute of Botany in the early 2015.Chiral dihydrocoumarin derivatives are a class of compounds widely distributed in nature.These compounds have attracted many pharmacologists and organic synthesis experts over the years that have anti-hypertension, antibacterial, anti-HIV,anti-cancer and other pharmacological activities.In the paper,we have tried four routes completing the total synthesis of the molecule.The key reaction of the first route is to complete the establishment of C-3 quaternary carbon center by Michael addition reaction between the molecules and then the Horner-Wadsworth-Emmons reaction to construct the alkyl side chain connected with C-4;The second route tried doing first esterification reaction and intramolecular Michael addition reaction;In the third route,1-4 addition reactions were made with the lithium reagent and α, β-unsaturated carbonyl compound and then the product is reacted with a substituted nucleophilic allyl bromide to give the key intermediate compound;The last route we want to Friedel-crafts reaction to bulid a first intermediate,but we failed to succeed according to many reaction conditions.Although not been able to get the desired product we want finally, we synthesized a number of key intermediates,as well as follow-up to the completion of the total synthesis of the compound provides ideas and experimental evidence.The next step is to explore a more reasonable and practicable route and synthesize the desired product eventually.