First total synthesis of two new diglycosides, neohancosides A and B, from Cynanchum hancockianum
作者:Yaeko Konda、Tsuneyuki Toida、Eisuke Kaji、Kazuyoshi Takeda、Yoshihiro Harigaya
DOI:10.1016/s0008-6215(97)00086-4
日期:1997.6
Abstract Neohancosides A (1) and B (2) are monoterpene diglycosides isolated from Cynanchum hancockianum , which is a Chinese folk medicine having antitumor activity. First total synthesis of 1 and 2 , (3 R )-linaloyl and (3 R )-8-hydroxylinaloyl 3- O - β -d-xylopyranosyl-(1 → 6)-β-d-glucopyranosides were achieved stereoselectively using fluoride 12b as a glycosyl donor. The asymmetry of C-3 in 1 and
摘要新汉果苷A(1)和B(2)是从汉防草中分离出的单萜二糖苷,这是一种具有抗肿瘤活性的中草药。使用氟化物12b立体选择性地完成1和2的第一个全合成,(3 R)-芳基酰基和(3 R)-8-羟基芳基酰基3-O-β-d-吡喃吡喃糖基-(1→6)-β-d-吡喃吡喃糖苷。作为糖基供体。通过分离(3 R),(3 S)-芳酰基和(3 R),(3 S)-8-苯甲酰氧基芳醛基3-O -2,3, 4-三-O-苯甲酰基-β-d-吡喃葡萄糖苷,分别为19和21以及20和22。1和2的绝对构型由合成中间体33和34的酶促降解确定。