A New Synthesis of Dihydrocapsaicin and Its Related Compounds

• Main Authors: Chung-Chin Wu, 吳仲欽
• Other Authors: Eng-Chi Wang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/f4q2x7

碩士 === 高雄醫學大學 === 化學系碩士班 === 91 === I. Preparation of nitriles： In our previous study, we have developed a new method for the preparation of nitriles by the reaction of aldehydes, hydroxylamine, and phthalic anhydride in one pot. We have studied another reaction condition, by fusing oxime and phthalic anhydride in 5-minutes to give the desired nitriles. In this thesis, more entries are studied. II. Synthesis of dihydrocapsaicin, and its carbons chain analogs. The 4-Benzyloxy-3-methoxybenzylamine, prepared from the reduction of 4-Benzyloxy-3-methoxybenzylnitrle, was reacted with ε-caprolactone or δ-valerolactone at neat condition to give 4-benzyloxy-3- methoxybenzyl(5-hydroxy)pentanamide, and 4-benzyloxy-3-methoxy- benzyl(6-hydroxy) hexanamide, These hydroxylamides were oxidized to corresponding aldehydes by Swern oxidation. Then, by reacting of these aldehydes with isobutyltriphenylphosphonium bromide and potassium tert-butoxide to undergo Wittig reaction gave a mixture of Z-form and E-form of benzyl-protected capsaicins, and its carbon chain analogs, respectively. The mixture of Z-form and E-form which not separated, was directly subjected to saturate the double bond, together with deprotection of O-benzyl group by hydrogenation in the presence of palladium catalyst, gave dihydrocapsaicin, a minor component of capsicium plants, and its 9-carbons chain analogy in good all-over yield.