A straightforward chiral pool synthesis for a non-natural calystegin, 3-epi-B2, is described. Key steps of this synthesis include an ultrasound-assisted Zn-mediated tandem ring opening reaction followed by a Grubbs’ catalyst-mediated ring closure metathesis reaction. Compared to calystegin B2, the target compound is no longer an inhibitor for a β -glycosidase hence proving that an equatorial hydroxyl group at position C-3 is necessary for a tight binding of calystegins into the active site of β -glycosidases.
本文描述了一种直接手性池合成非天然的卡利斯特吉因3-epi-B2的方法。该合成的关键步骤包括超声波辅助下的Zn介导的串联环开放反应,随后是Grubbs催化剂介导的环闭合转化反应。与卡利斯特吉因B2相比,目标化合物不再是β-葡萄糖苷酶的抑制剂,从而证明C-3位置的赤道羟基团对于卡利斯特吉因紧密结合到β-葡萄糖苷酶的活性位点中是必要的。