Hydroalkylation leading to heterocyclic compounds. Part 1: New strategies for the synthesis of polysubstituted 2H-pyran-2-ones
作者:Wei-Bing Liu、Huan-Feng Jiang、Chun-Li Qiao
DOI:10.1016/j.tet.2008.12.069
日期:2009.3
Polysubstituted 2H-pyran-2-ones and 5,6-dihydro-2H-pyran-2-ones were synthesized via the MCRs initiated by the hydroalkylation of alkynoates with activated methylenes. Under the optimized reaction conditions, the desired products were obtained in 47–88% isolated yields. The experimental results showed that the groups on activated methylenes act important roles in the nucleophilic attack fashion.
Reaction Between 1,3-Dicarbonyl-Containing CH Acids and Dialkyl Acetylenedicarboxylates in the Presence of Silica Gel in Solvent-Free Conditions: An Efficient Method for the Synthesis of Electron-Poor Alkenes and Pyranes
作者:Ali Ramazani、Nader Noshiranzadeh
DOI:10.1080/00397910802517830
日期:2009.3.10
Abstract A two-component condensation reactionbetween a 1,3-dicarbonyl-containing CH acid and an electron-poor acetylenicester efficiently provides fully substituted electron-poor alkenes and pyranes in a one-pot reaction in the presence of silica gel in solvent-free conditions.
Synthesis of Polysubstituted α-Pyrones Using Zinc-Catalyzed Addition-Cyclization Reactions
作者:Wei-Bing Liu、Cui Chen、Qing Zhang、Zhi-Bo Zhu
DOI:10.1002/jhet.1698
日期:2014.9
Various polysubstituted α‐pyrone derivatives have been directly synthesized via a hydroalkylation of Michael additional reaction following a cyclized process catalyzed by the Lewis acid of Zn(OAc)2. This protocol provides a new convenient and step‐economical route to construct heterocycles. Fourteen examples are obtained from easily available materials with moderate to good yields.