Abstract
We have synthesized artepillin C, a diprenylated p-hydroxycinnamate originally isolated from Brazilian propolis and exhibiting antioxidant and antitumor activities, from 2,6-diallylphenol. Replacement of the terminal vinyl with 2,2-dimethylvinyl group by olefin cross-metathesis and subsequent transformation yielded 2,6-diprenyl-1,4-hydroquinone diacetate. Candida antarctica lipase B-catalyzed deacetylation in 2-propanol regioselectively removed the less hindered acetyl group to give 2,6-diprenyl-1,4-hydroquinone 1-monoacetate. After triflation of the liberated 4-hydroxy group, a three-carbon side chain was introduced by palladium-mediated alkenylation with methyl acrylate. Final hydrolysis of the esters furnished artepillin C.
摘要:我们从2,6-二烯基苯酚合成了artepillin C,它是一种源自巴西蜂胶的二烯基化p-羟基肉桂酸,具有抗氧化和抗肿瘤活性。通过烯烃交叉重聚将末端乙烯基替换为2,2-二甲基乙烯基,并进行后续转化,得到了2,6-二烯基-1,4-对苯醌二乙酸酯。在2-丙醇中,Candida antarctica脂肪酶B催化去乙酰化,选择性地去除了障碍较小的乙酰基,得到了2,6-二烯基-1,4-对苯醌1-单乙酰酸酯。在游离的4-羟基上进行三氟甲磺酰化后,通过钯介导的丙烯酸甲酯烯丙基化引入了一个三碳侧链。最后,酯的水解得到了artepillin C。