Orgnic Photochemical Study On Its Application In Synthesis Of (+)-Licarin B

Organic photochemical synthesis is an important part of modern organic chemistry,that mainly focuses on a series of reactions when organic compound is stimulatedunder light. The substrate molecule happens electron transition after it is stimulated bylight. There is an high energy electron which can take another in electronic form at thesame time it is easy to leave with high activity in the outer orbit. The stimulatedmolecular is a kind of high reactivity of intermediate, it can implement many reactionswhich are difficult to happen in common conditions. Therefore organic photochemistryreactions have the very high economic value and the significant research significance.(+)-Licarin B is a kind of new lignan compounds with2,3-dihydrobenzofuranring-system constitute. It has multiple activities on bio-pharmacology. But there are notplenty of reports about its total synthesis, and the traditional total synthesis ways havemany shortcomings. Organic photochemical synthesis has made rapid development inthese years with advantages of high efficiency, specificity, low energy consumption, andhigh yield rate. The task of this paper is to apply organic photochemistry to the totalsynthesis of (+)-Licarin B.In this paper, the photochemical synthesis methods of (+)-Licarin B has beenexplored. Through the comparison of different synthesis routes, this paper regards5-Bromo-2-hydroxyacetophenone as the initial raw material, experienced Phenolichydroxyl protection, carbonyl protection, formylation reaction, deprotection, acetylprotection, UV induced Fries rearrangement, ether reaction, the o-Aryl ketone ether isobtained. Regarding the o-Aryl ketone ether as the photochemical precursor, the Norrishtype II reaction completes and generates a benzodihydrofuran compound with the300nm UV-light source. The preparation of the benzodihydrofuran compound for thetotal synthesis of (+)-Licarin B work laid a good foundation.