An intramolecular formal [3 + 2] cationic cycloaddition between benzylic carbocation and styrene was developed for the totalsynthesis of codonopiloneolignanin A. Further study shows benzocycloheptene as a good substrate for 1,3-dipolar cycloaddition, and a model studytoward cephalocyclidine A skeleton was reported.
开发了一种苄型碳正离子和苯乙烯之间的分子内形式 [3 + 2] 阳离子环加成反应,用于全合成 codonopiloneolignanin A。进一步研究表明,苯并环庚烯是 1,3-偶极环加成反应的良好底物,并且对头环素 A 骨架进行了模型研究。报道。
Synthetic Studies on Amphirionin-5: Stereochemical Assignment/Reassignment of the C1–C9 Portion through Stereodivergent Synthesis
作者:Moemi Kanto、Makoto Sasaki
DOI:10.1021/acs.orglett.5b03346
日期:2016.1.4
Synthesis of fourdiastereomers of the C1–C12 fragment of amphirionin-5 has been achieved in a convergent and stereodivergent manner. Detailed comparison of the 1H and 13C NMR data of each compound with those reported for the naturalproduct led to not only the stereochemical assignment of the relative configuration of the C4/C5 stereogenic centers but also reassignment of the proposed relative configuration
amphirionin-5的C1-C12片段的四种非对映异构体的合成已经以收敛和立体发散的方式实现。每种化合物的1 H和13 C NMR数据与天然产物的详细比较,不仅导致立体化学指定C4 / C5立体异构中心的相对构型,而且还重新分配了拟议的C9 / C5相对构型。 amphirionin-5。
Stereodivergent Synthesis and Configurational Assignment of the C1–C15 Segment of Amphirionin-5
The relative configuration of the C3–C12 portion of amphirionin-5, a novel marine polyketide with potent cell proliferation-promoting activity, was established by the stereodivergent synthesis of six diastereomeric model compounds and comparison of their NMR spectroscopic data with those reported for the natural product. This study led to the elucidation of the relative configuration between C4/C5
Multiple Rhodium-Catalyzed Cleavages of Single C–C bonds
作者:Christophe Aïssa、Damien Crépin、Daniel J. Tetlow、Kelvin Y. T. Ho
DOI:10.1021/ol400266g
日期:2013.3.15
The Rh(I)-catalyzed intramolecularhydroacylation of cis and trans asymmetrically substituted alkylidenecyclobutanes proceeds according to three mechanistic pathways. As shown by deuterium-labeling experiments, the mechanism accounting for the rearrangement of the cis isomers includes the cleavage of three carbon–carbon bonds and a remarkable transannular 3-exo-trig carbometalation.
Convergent Stereoselective Synthesis of the C16–C37 Subunit of Sorangicin A
作者:Satyanarayana Nyalata、Sadagopan Raghavan
DOI:10.1021/acs.orglett.9b02729
日期:2019.10.4
disclosed using an α-chloro sulfide for C–C bond formation. The key intermediate, an α,β-unsaturated ketone, is revealed by a [2,3] sigmatropic rearrangement of a propargylic sulfoxide. Three disparate approaches are detailed to create the C25 carbinol stereocenter. The cis-2,6-disubstitution of the THP ring is secured by ionic hydrogenation. A cross-metathesis reaction and Julia–Kocienski olefination