The Synthesis Of Shikimic Acid Derivatives And Study Of Selective Protection On Hydroxyl Groups

The application of the protection groups on synthesis of natural product is not only unavoidable, but also extraordinary effective. The functional groups, such as the hydroxyl groups, especially the 1, 2-dihydroxyls, is very popular in the natural products or other compounds which is designed to synthesize, leading to develop a lot of protecting groups, which can sum up three kinds, such as the esters, the ethers and the acetals, the ketals. Free hydroxyls can be protected through the acetal or ketal reaction, because the ketones can easily produce the compounds containing the five rings with the syn-orth-OHs, or the aldehyds can form the six rings with the 1, 3-di-OHs.The protecting groups of the ketone which are introduced to and then removed from the hydroxyl groups under the mild reaction conditions, possess the good regioselectivity and chemistry-selectivity, thus, it's widely used in the field of organic synthesis.The compound of (3R,4S,5R)-3,4,5-trihydroxycyclohex-l-enecarboxylic acid, I.e. the shikimic acid, as the starting material to protect the functional groups of the hydroxyl group using the protecting groups of the ketone, is studied and researched the selective protection on the polyhydroxy groups. The synthesis technology is the foundation on the study of the new drugs, thus, the designed process is checked if it is feasible or not through preliminary experiment after referring to a large many of documents, then to grope the experiment condition with the feasible experimental scheme. The polyhydroxy groups protecting reaction are carried out under the optimal condition which is found through contrast and sieving to improve the experiment condition, in order to increase the yield of the target compounds, eventually their structures are determined by melting point, ~1HNMR and so on.At the same time, there are two new compounds synthesized through experimental reaction, which all contain the structure of the benzene rings identified by ~1HNMR, and the two new compounds belonging to the aromatic compounds show that a new process is found to synthesis the compound containing the benzene rings.There are four shikimic acid derivatives and two new compounds synthesized, which are the compounds of (3aR,7R,7aS)-7-hydroxy-2,2-dimethyl-3a,6,7,7a-tetrahydrobenzo[d][1,3]dioxole-5-carboxylate ethyl ester(abbreviated to MCSY-1), (3aR,7R,7aS)-2,2-diethyl-7-hydroxy-3a,6,7,7a-tetrahydrobenzo[d] [1,3]dioxole-5-carboxylate ethyl ester (abbreviated to MCSY-2), (4R,4aR,10aR)-4-hydroxy-5a,9a-dimethoxy-1,4,4a,5a,6,7,8,9,9a,10a-decahydrod ibenzo[b,e][1,4]dioxine-2-carboxylate ethyl ester(abbreviated to MCSY-3), (3R,4S,5R)-4,5-dihydroxy-3-(pentan-3-yloxy)cyclohex-1-enecarboxylate ethyl ester(abbreviated to MCSY-4), 5a,9a-dimethoxy-5a,6,7,8,9,9a-hexahydrodibenzo [b,e][1,4]dioxine-2-carboxylate ethyl ester(abbreviated to MCSY-5), 5a,9a-dimethoxy-5a,6,7,8,9,9a-hexahydrodibenzo[b,e][1,4]dioxine-2-carboxylate methyl ester(abbreviated to MCSY-6). Meanwhile, the study on synthesis of 1, 2-cyclohexanedione which protects the 1, 2-dihydroxyl group is carried out to increase its yield.