Simple Synthesis of Sakuranetin and Selinone via a Common Intermediate, Utilizing Complementary Regioselectivity in the Deacetylation of Naringenin Triacetate
Simple Synthesis of Sakuranetin and Selinone via a Common Intermediate, Utilizing Complementary Regioselectivity in the Deacetylation of Naringenin Triacetate
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DOI：
10.1248/cpb.c16-00190
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发表时间：
2016-07-01
影响因子：
1.7
通讯作者：
Sugai, Takeshi
中科院分区：
文献类型：
--
作者：
Yamashita, Yasunobu;Hanaya, Kengo;Sugai, Takeshi
利用柚皮素三乙酸酯的区域选择性脱乙酰化反应，成功地合成了樱花素和selinone。后者在C-7用咪唑在1，4-二氧六环中在40 ℃脱乙酰化，得到相应的二乙酸酯，产率为80%。将所得游离羟基甲基化并随后除去剩余的两个乙酰基，得到樱花素，其先前以71%的总产率作为抗稻瘟病真菌Pyricularia pesticides的植物抗毒素分离。相同的中间体，柚皮素三乙酸酯，在四氢呋喃中与2-丙醇进行酯交换反应，由Candida anastritica脂肪酶B催化。观察到C-4'脱乙酰化的对比区域选择性偏好，以82%的产率得到异构体二乙酸酯。游离羟基在Mitsunobu条件下异戊烯化，随后脱保护，得到selinone，其先前从Monotes engleri中分离并表现出对白色念珠菌的抗真菌活性，总收率为55%。
Sakuranetin and selinone were successfully synthesized utilizing the regioselective deacetylation of naringenin triacetate. Deacetylation of the latter at C-7 with imidazole in 1,4-dioxane at 40 degrees C furnished the corresponding diacetate in 80% yield. Methylation of the obtained free hydroxy group and subsequent removal of the remaining two acetyl groups gave sakuranetin, which was previously isolated as a phytoalexin against rice blast disease fungus, Pyricularia oryzae, in 71% overall yield. The same intermediate, naringenin triacetate, was subjected to transesterification with 2-propanol in tetrahydrofuran, catalyzed by Candida antarctica lipase B. A contrasting regioselective preference for C-4' deacetylation was observed, giving an isomeric diacetate in 82% yield. Prenylation of the free hydroxy group under Mitsunobu conditions and subsequent deprotection furnished selinone, which was previously isolated from Monotes engleri and exhibits antifungal activity against Candida albicans, in 55% overall yield.