Total Synthesis of an Atropisomer of the
<i>Schisandra</i>
Triterpenoid Schiglautone A
作者:Binjie Ma、Yifan Zhao、Chi He、Hanfeng Ding
DOI:10.1002/anie.201809076
日期:2018.11.19
A diastereoselective approach for the total synthesis of an unusual atropisomer of the Schisandra triterpenoid (±)‐schiglautone A is described. The efficient synthetic strategy features three key transformations: 1) two sequential titanium(III)‐catalyzed radical cyclization/homologation reactions to construct the trans‐fused [6,7] bicycle as well as install the quaternary carbons at C10 and C14 with
A concise, stereoselective, and protecting-group-freetotalsynthesis of aplykurodinone-1 from Hajos–Parrish ketone was described. The synthetic approach features a sequence of aerobic allylic oxidation and elimination of alcohol 9. The key intermediate for this synthesis was formed by a stereoselective intramolecular radical cyclization.
applied as an effective catalyst in the dehydrative cyclization and subsequent rearrangement of unsaturated tertiary alcohols. This is the first report on catalyzing such a reaction with a Brønsted acid. Scope and limitations of this cyclopentene‐forming reaction sequence are presented. Furthermore, substrate‐selective conversion as well as competitive inhibition are described and provide evidence
作者:Gang Liu、Guangjian Mei、Runwen Chen、Haina Yuan、Zhen Yang、Chuang-chuang Li
DOI:10.1021/ol502220r
日期:2014.9.5
The concise total synthesis of aplykurodinone-1 with an unusual cis-fused hydrindane moiety has been accomplished without the need for any protecting group chemistry using a unique SmI2 mediated reductive cascade cyclization reaction and a direct cuprate mediated 1,4-addition. This work represents the first example of the use of a SmI2-mediated intramolecular cascade cyclization reaction between “halide
Asymmetric Total Syntheses of Euphol and Tirucallol
作者:Joshua M. Nicholson、Glenn C. Micalizio
DOI:10.1021/acs.orglett.3c02187
日期:2023.8.4
Asymmetric de novo syntheses of euphol and tirucallol have been accomplished by way of a concise sequence of chemical steps featuring several modern stereoselective transformations. The preparative solution described for these complex problems in natural product synthesis departs significantly from biomimetic polyene cyclization chemistry, which has been leveraged to address related tetracyclic triterpenoid