The Synthesis And Biological Activity Of Talienbisflavan A Intermediates And Aryl Sulfones

Talienbisflavan A is a natural tannins product, which was isolated from tea in2012.The preliminary biological activity tests show that it has some functions such as antioxi-dant and eliminating free radicals, which are good to health. We plan to synthesizetalienbisflavan A by organic synthesis and accomplished the synthesis of three related keyintermediates. Moreover, we also study the synthesis method and biological activity of arylbenzyl sulfones.Talienbisflavan A is synthesized with phenols as the starting materials. The first moi-ety of talienbisflavan A is obtained from phloroglucinol via the Bn-protection of the threephenolic hydroxyl groups of phloroglucinol followed by selective removing one of theBnO protections. The second moiety of talienbisflavan A is synthesized from2,4,6-trihydroxybenzaldehyde through selective Bn-protection of the two phenolic hydrox-yl groups of2,4,6-trihydroxybenzaldehyde, and reduction of the aldehyde group to the hy-droxyl group. The third moiety of talienbisflavan A is prepared from pyrocatechol by se-lective aromatic bromination and Bn-protection of the phenolic hydroxyl groups. A water-promoted ortho-selectivemonohydroxymethylation of phenols in NaBO2system has beendeveloped in the transformation of the first moiety to the second moiety of talienbisflavanA.The above Bn-protection belongs to indirect nucleophilic substitution of benzyl alco-hols, consisting of functionalization of the hydroxyl group to a bromide group, and subse-quently substitution of the resulting benzyl bromides. In this thesis, direct nucleophilicsubstitution of benzyl alcohols with TosMIC has been developed. The reaction conditionswere optimized by screening various catalysts, solvents, additives, temperature and reac-tion time. The optimized reaction conditions are summarized as follows: the best catalyst isBiBr3; the best solvent is CH3NO2; the best additive is AcOH; the best reaction temperatureis room temperature; the practical reaction time is20-30h. Under the optimized condition,phenyl benzyl sulfones can be obtained. The products are identified with1H NMR,13CNMR, HR-MS and IR.The synthesis of aryl sulfones has attracted much attention due to their promising an-tibacterial, antifungal and antitumor activities. Accordingly, the syntheses of new arylbenzyl sulfones are performed in this field. Tests are made to check the antibacterial andantitumor activity of aryl benzyl sulfones based on K-B and MTT methods. The resultsshow that parts of the compounds have some antibacterial activity. Three compounds haveobvious inhibitory effect on tumor cell HL-60, which might have pharmaceutical potential-ity.