Division of Organic Chemistry, ‡Academy of Scientific and Innovative Research, and §Centre for Material Characterization, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune 411 008, India.
Org Lett. 2017 Jul 7;19(13):3564-3567. doi: 10.1021/acs.orglett.7b01525. Epub 2017 Jun 14.
A one-pot biomimetic synthesis of (-)-angiopterlactone B and its enantiomer (+)-angiopterlactone B has been accomplished via TBAF-catalyzed tandem ring contraction followed by oxa-Michael/Michael addition sequence. Comparison of specific optical rotations, absolute configurations, and CD spectra of natural, synthesized (-)-angiopterlactone B and (+)-angiopterlactone B unequivocally proves that the isolated angiopterlactone B must be levorotatory. Synthesis of hitherto undiscovered natural products 18 and 20 and analogues of angiopterlactone B demonstrate the versatility of this method.
通过 TBAF 催化的串联环收缩，随后进行氧杂迈克尔/迈克尔加成序列，实现了(-)-angiopterlactone B 和其对映异构体 (+)-angiopterlactone B 的一锅仿生合成。天然、合成(-)-angiopterlactone B 和 (+)-angiopterlactone B 的比旋光度、绝对构型和 CD 光谱的比较，明确证明分离出的 angiopterlactone B 必须是左旋的。迄今未发现的天然产物 18 和 20 以及 angiopterlactone B 的类似物的合成证明了该方法的多功能性。
