undergoes intramolecular cyclization in the presence of a [Pd(iPr2PC2H4PiPr2)] catalyst to give a mixture of cyclohexanone and cycloheptenone derivatives. The cyclohexanone 2-(1-hydroxyethyliden)-3-vinylcyclohexanone isomerizes in the presence of palladium to give the palladium-alkene complex whose crystal structure has been established by X-ray diffraction. A related cyclization reaction involving the
在[Pd(i Pr 2 PC 2 H 4 P i Pr 2)]催化剂,得到环己酮和环庚烯酮衍生物的混合物。在钯存在下,环己酮2-(1-羟乙叉基)-3-乙烯基环己酮异构化,得到钯-烯烃配合物其晶体结构已通过X射线衍射确定。涉及双取代的1,3-二酮9-羟基-1,3,7,12,14-戊烯-7-一的相关环化反应导致螺环化合物(主要是5,11-二乙烯基螺环)的混合物形成[5.5] undeca-1,7-dione)的结构已通过2 D-NMR技术借助1 H-和13 C-NMR光谱学得以阐明。
Total Synthesis of Yuzurine-type Alkaloid Daphgraciline
作者:Li-Xuan Li、Long Min、Tian-Bing Yao、Shu-Xiao Ji、Chuang Qiao、Pei-Lin Tian、Jianwei Sun、Chuang-Chuang Li
DOI:10.1021/jacs.2c09548
日期:2022.10.19
The first totalsynthesis of daphgraciline has been achieved, which also represents the first example of the synthesis of Daphniphyllum yuzurine-type alkaloids (∼50 members). The unique bridged azabicyclo[4.3.1] ring system in the yuzurine-type subfamily was efficiently and diastereoselectively assembled via a mild type II [5+2] cycloaddition for the first time. The compact tetracyclic [6–7–5–5] skeleton
实现了daphgraciline的首次全合成,这也代表了Daphniphyllum yuzurine型生物碱(~50个成员)合成的第一个例子。yuzurine 型亚家族中独特的桥联氮杂双环[4.3.1] 环系统首次通过温和的 II 型 [5+2] 环加成反应高效且非对映选择性地组装。紧凑的四环 [6-7-5-5] 骨架通过分子内 Diels-Alder 反应有效安装,然后进行苯甲酸型重排。最终产品中具有合成挑战性的螺四氢吡喃部分通过 Ti III介导的还原性环氧化物偶联反应非对映选择性地安装。介绍了获得对映体富集 daphgraciline 的潜在途径。
Novel type of sex pheromone structure identified fromStigmella malella (Stainton) (Lepidoptera: Nepticulidae)
作者:Miklós Tóth、Gábor Szöcs、Erik J. van Nieukerken、Peter Philipp、Frank Schmidt、Wittko Francke
DOI:10.1007/bf02033659
日期:1995.1
Short-chain unsaturated chiral methyl carbinols are identified as a new class of lepidopteran pheromone components. The natural female-produced pheromone of the banded apple pigmy Stigmella malella (= Nepticula malella) (Stainton) (Lepidoptera: Nepticulidae) was identified to be a mixture of (S)-(E)-6,8-nonadien-2-ol and (S)-(Z)-6,8-nonadien-2-ol. For monitoring traps, a 10:3 E:Z blend at 100-1000 mu g is recommended. It is suggested that pheromones with similar structures may be specific to Nepticulidae and other related microlepidopteran families.
Jung, Michael E.; Miller, Steven J., Heterocycles, 1990, vol. 30, # 2, p. 839 - 853
作者:Jung, Michael E.、Miller, Steven J.
DOI:——
日期:——
Small-Ring Compounds. XLV. Influence of Vinyl and Phenyl Substituents on the Interconversion of Allylcarbinyl-Type Grignard Reagents<sup>1</sup>
作者:Merlin E. H. Howden、Adalbert Maercker、James Burdon、John D. Roberts
DOI:10.1021/ja00960a030
日期:1966.4
bromide was complete after 5 hr at room temperature. Less than 0.3% of the isomeric cyclopropylcarbinyl derivative, however, is in equilibrium with the ring-opened species. While reactions of the Grignard reagents normally expected to have anionic-type mechanisms were found to lead to allylcarbinyl products only, substantial amounts of cyclic products were formed with molecular oxygen.