Studies On The Total Synthesis Of Rocaglamide

The attempted total synthesis of natural product—Rocaglamide and its analogues was described in the dissertation. Rocglamide is the agent responsible for the anti-tumor, anti-leukemic and insecticidal activities of extracts from the roots and stems of Aglaia elliptifolia(Meliace). Its structure, determined by single-crystal X-ray analysis, was reported in 1982 by King etc. The synthesis of the tricyclic core structure of Cyclopenta[b]benzofuran skeleton bearing a highly functionalized cyclopentane moiety with five stereogenic centers is a challenge. A shorter, more convergent synthesis that allows an agrochemical application is needed. The main advancement of the new approach is inexpensive reagents, mild reaction conditions, and short synthesis route (7-8 steps) with higher yield. It is a new way to form the Cyclopenta[b]benzofuran skeleton with high stereoselectivity and desired stereochemistry of the five stereogenic centers. To achieve this aim, 6-Hydroxy-2,4-Dimethoxybenzaldehyde was synthesized by anhydrous phloroglucinol of Vilsmeier-Hack Reaction, followed by methoxymethylation partly. Then the product reacted with 4-hydroxypropiophenone by the saturation of HCl gas to prepare the flavylium salt which converted into the benzofuran structure by the oxidation of H2O2.This important intermediate was changed into the former structures of the target compounds by Adol and Knoevenagel reactions. The last step is to synthesize the cyclopentane ring which contains a cis-arrangement between the adjacent aryl and phenyl substituents by Nazarov cyclization. Several new compo -unds are synthesized, and most of them are mixtures according to 1H NMR spectru -ms. The main task is to find out the optimized reaction condition of the final step with high selectivity and yield to synthesize the target compound successfully in the near future.