Department of Chemistry , Hankuk University of Foreign Studies , Yongin 17035 , Korea.
J Org Chem. 2019 Jan 4;84(1):94-103. doi: 10.1021/acs.joc.8b02342. Epub 2018 Nov 16.
Total synthesis of both enantiomers of (-)-(2 S,3 R,6 S)- and (+)-(2 R,3 S,6 R)-microgrewiapine A along with (+)-microcosamine A and (-)-6- epi-microgrewiapine A from chiral 1-(α-methylbenzyl)-aziridine-2-carboxylate was accomplished for the first time. Key steps involved in this synthesis include one-pot reductive ring-opening of aziridine, debenzylation, intramolecular N-alkylation to obtain the key piperidine ring, and Julia-Kociensky olefination. The absolute configuration of natural microgrewiapine A is assigned as (+)-(2 R,3 S,6 R), which is opposite to the originally proposed structure by comparing optical rotation data of both synthetic enantiomers.
首次从手性 1-(α-甲基苄基)-氮杂环丁烷-2-羧酸酯出发，全合成了（-）-（2S,3R,6S）-和（+）-（2R,3S,6R）-微鹅掌揪碱 A 及其对映异构体（+）-小环澳洲茄胺 A 和（-）-6- epi-微鹅掌揪碱 A。该合成的关键步骤包括一步还原开环氮杂环丁烷、脱苄基、分子内 N-烷基化得到关键的哌啶环，以及 Julia-Kociensky 烯烃化。天然微鹅掌揪碱 A 的绝对构型被确定为（+）-（2R,3S,6R），与最初通过比较两种合成对映异构体的旋光数据提出的结构相反。
