From Planning to Optimization: Total Synthesis of Valerenic Acid and Some Bioactive Derivatives
作者:Juergen Ramharter、Johann Mulzer
DOI:10.1002/ejoc.201101834
日期:2012.4
The streamlined synthesis implements a new one-pot reaction, which combines the addition of a Grignard species with an acid-catalyzed isomerization of the intermediate allylic alcohol. Further highlights are a stereo- and regioselective hydroxy-directed Diels–Alder reaction, a hydroxy-directed hydrogenation, and a final Negishi coupling reaction. After optimization of our synthesis, the preparation
Efficient and Scalable One-Pot Synthesis of 2,4-Dienols from Cycloalkenones: Optimized Total Synthesis of Valerenic Acid
作者:Juergen Ramharter、Johann Mulzer
DOI:10.1021/ol202170c
日期:2011.10.7
A mild and selective one-pot procedure to provide 2,4-dienols from simple cycloalkenones in high yields is described. This transformation is based on the in situ formation of acid-labile allylic alcohols, which on treatment with trifluoroacetic acid undergo a formal [1,3]-hydroxy migration to form diastereo- and enantiomerically enriched 2,4-dienols. The usefulness of this protocol is demonstrated in a short synthesis of valerenic acid.
Stereoselective Total Syntheses of Guanacastepenes N and O
作者:Shao-Zheng Peng、Chin-Kang Sha
DOI:10.1021/acs.orglett.5b01498
日期:2015.7.17
reaction and α-carbonyl radical cyclization. The quaternarycenters and their stereochemistry were established with sequential Cu(I)-mediated conjugate additions. A sequence with dihydroxylation, conjugate addition, and β-elimination was devised to incorporate all oxygen functionalities at positions. The total synthesis is adaptable for the synthesis of enantiopure guanacastepenes N and O using chiral intermediate