The Synthesis And Identification Of Capsaicin And Its Analogues

Capsaicin has many physical functions. It is applied widely in food and medicine industry. The chemosynthesis method of capsaicinoids is reported, and the synthesis method of primary amine is also reviewed in this paper.Anmine is widely applied in the field of organic synthesis.This paper, firstly, reviewed the common synthesis method of primary amine on the base of the research and application of it. In excessive methods used to syhthesize primary amine, this paper reviewed the reduction reaction, N-alkylation reaction, hydrolyzation reaction and rearrang- ment reaction.In order to research the influence of main funtional group to capsaicinoids'biological activities, we synthesize two important intermediates (A and B) used in the chemosynthesis of capsaicinoids and aslo synthesize three analogues of capsaicin by the retrosynthetic analysis of target molecule. In addition, we found out two methods of producing compound A for large-scale preparations of capsaicin and compared their advantages and disadvantages. Vanilline oxime prepared by vanilline was reduced to compound A in the first method. In another method, compound A was also observed with vanilline by following reactions: hydroxy protection of hydroxybenzene, reduction, chlorine-substitution and Gabrial. Part B is the enoic acid which is prepared by Bayer-Villiger oxidation reaction and Wittig reaction from cheap material—cyclohexanone. Sorbic acid and Isobutyric acid are used in the synthesis of analogues. In additon, many famous reactions are referred in the method, such as Wittig, Reimer- Tiemann, Gabriel, Bayer-Villiger and Sommelet reaction.Finally, the relation of chemical structure and biological activity is reported simply. At the same time, we present the synthesis methods and yields of target molecule and intermediates. The structure of intermediates and target molecule was indentified by IR, ¹H NMR, ¹³C NMR and MS. The main data was also studied.