Unusual aluminum chloride-assisted conversion of isopropenyl acetate into 3-acetyl- and 3,5-diacetyl-2,6-dimethyl- 4H-pyran-4-ones
作者:V. L. Novikov、O. P. Shestak、V. A. Denisenko
DOI:10.1007/s11172-010-0283-0
日期:2010.8
Reflux of isopropenylacetate with an excess of AlCl3 in 1,2-dichloroethane affords 3,5-diacetyl-2,6-dimethyl-4H-pyran-4-one in 17% yield. The mild acidic cleavage of the latter (2% HCl, 20 °C, 16 h) gives 3-acetyl-2,6-dimethyl-4H-pyran-4-one in 87% yield, whereas this reaction under more drastic conditions (17% HCl, reflux, 3 h) gives 2,6-dimethyl-4H-pyran-4-one in 61% yield.
[1+4] Cycloaddition of Isocyanides with3-(1-Hydroxyethylidene)pentane-2,4-dione. A Convenient Synthesisof Iminolactones†
作者:Ahmad Shaabani、Farhad Farrokhzad
DOI:10.1039/a703219f
日期:——
Isocyanides undergo formal [1+4] cycloaddition with3-(1-hydroxyethylidene)pentane-2,4-dione to afford five-memberediminolactone derivatives in high yields.