New syntheses of natural neoflavonoids and isoflavonoids

• Main Authors: Sie-Rong Li, 李協融
• Other Authors: Eng-Chi Wang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/26541022718564811139

博士 === 高雄醫學大學 === 藥學研究所 === 97 === Chapter I - New syntheses of neoflavonoids-dalbergichromene and dalbergin In this thesis, naturally occurring dalbergichromene and dalbergin were synthesized from a common neoflavene intermediate, which was derived from vanillin. The resultant neoflavene intermediate was debenzylated with AlCl3 to yield dalbergichromene in 39% total yield. Moreover, when the resultant neoflavene was oxidized by DDQ and followed by debenzylation with Pd(OH)2/C and cyclohexene in refluxing ethanol, dalbergin was given in 31% total yield. Chapter II - New syntheses of isoflavonoids-haginin E, equol, daidzein, and formononetin New syntheses of haginin E, equol, daidzein and formononetin are described in this chapter. Through a sequence of a Wittig reaction, O-alkylation, and another Wittig reaction, 4-benzyloxysalicylaldehyde, which was prepared from resorcinol in two steps, was converted into the desired intramolecular diene in one pot. Subsequently, the prepared diene was subjected to ring-closing metathesis using Grubbs’ catalyst (II) to construct the desired isoflavene intermediate. From the resultant isoflavene, certain isoflavonoids such as haginin E, equol, daidzein, formononetin and other related compounds were derived smoothly in good overall yields.