天然物異丹參酚酸C是從唇形科植物華鼠尾的水萃物所分離出來的新化合物,屬於酚羧酸酯類化合物,異丹參酚酸C的結構是由藤紫丹酸B與丹參素結合而成,藤紫丹酸B的結構中具有一個二苯㗁呯之骨架,異丹參酚酸C具有抗氧化活性,藤紫丹酸B具有神經保護之活性,由於異丹參酚酸C在植物中的含量非常少又無全合成之報導,本論文中主要針對異丹參酚酸C進行全合成之研究。以(4,5-bis(benzyloxy)-2-bromobenzyl)bromotriphenylphosphorane和3-benzyloxy-6-bromo-2-hydroxybenzaldehyde為起始物,以芐基作為保護基,經9個步驟完成異丹參酚酸C的全合成,藤紫丹酸B的部分是經由Wittig reaction及Ullmann condensation兩種方法合成出,然後丙烯酸的部分是利用Heck reaction合成出來的,丹參素的立體化學結構是利用Sharpless asymmetric dihydroxylation建立出來的。
Isosalvianolic acid C, a depside, was previously isolated from water extract of Salvia chinensis as a new natural product. The structure of isosalvianolic acid C is composed of tournefolic acid B and danshensu. Tournefolic acid B possessed a dibenzooxepine skeleton. Isosalvianolic acid C showed anti-oxidative activity. Tournefolic acid B was found to show neuroprotective effects. Due to limited amounts of isosalvianolic acid C from natural source and no synthetic work previously, in this thesis, the total synthesis of isosalvianolic acid C was carried out. The total synthesis of isosalvianolic acid C was accomplished in 9 steps starting from (4,5-bis(benzyloxy)-2-bromobenzyl)bromotriphenylphosphorane and 3-benzyloxy-6-bromo-2-hydroxybenzaldehyde. In this research, benzyl groups were used for protection of hydroxyl groups. The Wittig reaction and Ullmann condensation were used to construct the dibenzooxepine skeleton in tournefolic acid B moiety. The Heck reaction was used for coupling acrylic acid moiety to dibenzooxepine skeleton. The stereochemistry of danshensu moiety was established by Sharpless asymmetric dihydroxylation.