Total Synthesis and Absolute Stereochemical Assignment of Microgrewiapine A and Its Stereoisomers
作者:Lingamurthy Macha、Hyun-Joon Ha
DOI:10.1021/acs.joc.8b02342
日期:2019.1.4
Total synthesis of both enantiomers of (−)-(2S,3R,6S)- and (+)-(2R,3S,6R)-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
(-)-(2 S,3 R,6 S)-和(+)-(2 R,3 S,6 R)-微草酮平A和(+)-微粘胺A和(-首次完成了由手性1-(α-甲基苄基)-氮丙啶-2-羧酸酯制备的)-6-表位-微草嘌呤A。合成中涉及的关键步骤包括一氧化氮丙啶的一锅还原开环,脱苄基作用,分子内N-烷基化以获得关键哌啶环和Julia-Kociensky烯化反应。天然微草硫平A的绝对构型指定为(+)-(2 R,3 S,6 R),通过比较两种合成对映异构体的旋光度数据,与最初提出的结构相反。