Infrared and nuclear magnetic resonance spectroscopic studies of the structure and dynamics of allylic magnesium compounds
作者:E Alexander Hill、Winston A Boyd、Hemnalini Desai、Amir Darki、Lymel Bivens
DOI:10.1016/0022-328x(95)06014-n
日期:1996.5
streching bONds, corresponding to C CH2 and C CD2 groups in equilibrating allylic isomers. The methylene resonances in the 13C NMR spectra of allylmagnesium bromide and chloride and methallylmagnesium bromide are broadened at low temperatures by an exchange process which appears to be the interconversion between the classical unsymmetrical allytic structures. Analogous changes are seen in the spectrum
烯丙基-和甲基烯丙基-d 2-溴化镁的红外光谱具有两个双键拉伸键,对应于平衡烯丙基异构体中的CCH 2和C 2 CD 2基团。13中的亚甲基共振烯丙基溴化镁和氯化物以及甲基烯丙基溴化镁的13 C NMR光谱在低温下通过交换过程扩大,这似乎是经典不对称解析结构之间的相互转化。在1,3-二甲基烯丙基氯化镁的光谱和烯丙基溴化镁的质子NMR光谱中可以看到类似的变化。交换的速率常数和激活参数已从线宽确定。与格利雅试剂不同,二甲基镁在四氢呋喃中的亚甲基共振在降低的温度下不会显着加宽,并且氘代试剂在红外光谱中没有两个明显的双键拉伸带。
Concise Total Synthesis of (−)-Bipolarolide D
作者:Shengling Sun、Qi Wei、Yufei Liu、Zhaohong Lu
DOI:10.1021/jacs.4c04059
日期:2024.5.29
Here we report the first and concise total synthesis of a complex ophiobolin-derived sesterterpene, bipolarolide D, which hinges on two strategic applications of pentafulvene: (1) enantioselective pentafulvene-involved [6+2] cycloaddition; (2) regioselective and diastereoselective pentafulvene-involved Heck cyclization. Late-stage selective allylic addition to the ketone moiety facilitates the successful
在这里,我们报告了一种复杂的蛇毒碱衍生的二倍萜内酯 D 的首次简明全合成,其取决于五富烯的两个战略应用:(1)对映选择性五富烯涉及的 [6+2] 环加成; (2)区域选择性和非对映选择性五富烯参与的Heck环化。后期选择性烯丙基加成到酮部分有利于侧链的成功安装。该策略通过模块化方法实现了首次对映选择性全合成。该合成将促进相关生物活性的研究,并为利用富烯作为其他复杂天然产物合成中的通用合成子提供合成蓝图。
Vapor-phase thermolyses of 3-hydroxy-1,5-hexadienes. II. Effects of methyl substitution
作者:Alfred. Viola、E. James. Iorio、Katherine K. N. Chen、George M. Glover、Ullhas. Nayak、Philip J. Kocienski
DOI:10.1021/ja00990a019
日期:1967.7
Lehmkuhl,H. et al., Justus Liebigs Annalen der Chemie, 1975, p. 119 - 144
作者:Lehmkuhl,H. et al.
DOI:——
日期:——
Andersen, Marc W.; Hildebrandt, Bernhard; Koester, Gerhard, Chemische Berichte, 1989, vol. 122, p. 1777 - 1782
作者:Andersen, Marc W.、Hildebrandt, Bernhard、Koester, Gerhard、Hoffmann, Reinhard W.