Chalcogenopyranones from disodium chalcogenide additions to 1,4-pentadiyn-3-ones. The role of enol ethers as intermediates
作者:Kristi Leonard、Marina Nelen、Madhavi Raghu、Michael R. Detty
DOI:10.1002/jhet.5570360322
日期:1999.5
chalcogenides to give mixtures of products in which the chalcogenopyranones 1 are minor components and the dihydrochalcogenophenes 3 are the major products. The addition of hydrogensulfide to diynone 2b in ethanol gives a productmixture nearly identical to that observed for the addition of disodium sulfide in sodium ethoxide in ethanol to 2b. Intermediates for the addition of hydrogen chalcogenides and
Sequential [3+2] and [4+4] Annulation of Diynone and <i>o</i>‐Hydroxyaryl Azomethine Ylide: Construction of Dihydropyrrole Fused Eight‐Membered Ring Scaffold
作者:Jie Shen、Yu Xing、Lidong Fu、Yanze Li、Lei Cui、Zijun Zhou、Chunju Li、Jian Li
DOI:10.1002/adsc.202300998
日期:2023.12.5
We developed a cascade reaction of diynone and o-hydroxy aromatic aldimine under mild conditions. This protocol is proposed to proceed through sequential [3+2]/[4+4] cycloaddition and proton transfer processes, thus providing an efficient way for the synthesis of a variety of dihydropyrrole fused eight-membered ring scaffolds.
concise and efficientsynthesis of fully substituted cyclobutane derivatives from 1,4-diyn-3-ols and anhydrides was developed. Mechanistic studies indicated that a tandem esterification, isomerization to give allenyl ester, and homointermolecular [2+2] cycloaddition might be involved. The features of this protocol are its operational practicality, mild reaction conditions, and highregio- and stereoselectivity