Reagent Control of [1,2]-Wagner-Meerwein Shift Chemoselectivity Following the Nazarov Cyclization: Application to the Total Synthesis of Enokipodin B
作者:David Lebœuf、Christopher M. Wright、Alison J. Frontier
DOI:10.1002/chem.201203395
日期:2013.4.8
carbon framework of various sesquiterpenes from the herbertane and cuparane families is described, including the concise total synthesis of enokipodin B. The key step is the construction of the vicinal quarternary centers of the skeleton through a tandem Nazarovcyclization/Wagner–Meerwein rearrangement mediated by a copper(II) complex. During this study, it was also found that changing the ligand architecture
Enantioselective palladium catalyzed conjugate additions of ortho-substituted arylboronic acids to β,β-disubstituted cyclic enones: total synthesis of herbertenediol, enokipodin A and enokipodin B
作者:Jeffrey Buter、Renée Moezelaar、Adriaan J. Minnaard
DOI:10.1039/c4ob01085j
日期:——
Palladium catalyzed asymmetric conjugate addition of ortho-substituted arylboronic acids to cyclic enones and its application in natural product synthesis.
Synthesis of Cyclopentenones with C4-Quaternary Stereocenters via Stereospecific [3,3]-Sigmatropic Rearrangement and Applications in Total Synthesis of Sesquiterpenoids
作者:Weiping Zhou、Arnaud Voituriez
DOI:10.1021/jacs.1c07966
日期:2021.10.27
A cationic gold(I)-catalyzed asymmetric [3,3]-sigmatropic rearrangement of sulfonium leads after cyclization to cyclopentenones with a C4-quaternary stereocenter. Starting with simple vinyl sulfoxides and propargyl silane, numerous compounds were isolated with moderate to good yields and excellent enantiomeric excesses (26 examples). The application of this simple methodology allowed the efficient
锍的阳离子金 (I) 催化不对称 [3,3]-σ 重排在环化后生成具有 C4-季立体中心的环戊烯酮。从简单的乙烯基亚砜和炔丙基硅烷开始,以中等至良好的收率和优异的对映异构体过量分离了许多化合物(26 个实例)。应用这种简单的方法可以有效地合成五种天然倍半萜类化合物,包括 enokipodin A 和 B、hitoyopodin A、lagopodin A 和 isocuparene-3,4-diol。
Total Syntheses of Enokipodins A and B Utilizing Palladium-Catalyzed Addition of An Arylboronic Acid to An Allene
作者:Masahiro Yoshida、Yasunobu Shoji、Kozo Shishido
DOI:10.1021/ol9001637
日期:2009.3.19
The enantioselective total syntheses of enokipodins A and B, alpha-cuparenone-type sesquiterpenoids with antimicrobial activity, have been achieved. The key step is the enantiospecific construction of the quaternary carbon center using a palladium-catalyzed addition of an arylboronic acid to an allene followed by an Eschenmoser-Claisen rearrangement.
Highly oxidized cuparene-type sesquiterpenes from a mycelial culture of Flammulina velutipes
Cuparene-type sesquiterpenes were isolated from a culture broth of Flammulina velutipes (Curt.:Fr.) Sing. Using spectroscopic methods (HR-MS,H-1 and C-13 NMR, and 2D NMR, spectroscopy), their structures were determined to be 2,3,4,5-tetrahydro-2,7-dihydroxy-5,8,10,10-tetramethyl-2,5-methano-1-benzoxepin and 5-methyl-2-(3-oxo-1,2,2-trimethylcyclopentyl)benzoquinone. Both showed antimicrobial activity against Cladosporium herbarum and Bacillus subtilis. (C) 2000 Elsevier Science Ltd. All rights reserved.