Silver Ion-assisted Solvolysis of 2,2-Dibromo-1-phenylcyclopropanecarboxylic Acid: Solvent-dependent Competition between Decarboxylation and Ring Closure.
作者:Leiv K. Sydnes、Rajesh Mungaroo、John S. Svendsen、Jacek Stawinski
DOI:10.3891/acta.chem.scand.52-1392
日期:——
The solvolysis of the title compound has been studied in several alcohols (methanol, 2,2,2-trifluoroethanol, isopropyl alcohol, tert-butyl alcohol and 1,I,1,3,3,3-hexafluoro-2-propanol [HFP]) in the presence of an excess of sliver trifluoroacetate. In all solvents the corresponding butenolide, 4-bromo-3-phenyl-2(SH)-furanone, was a major or the predominant product. Another product formed in all solvents but HFP was (Z)-4-alkoxy-3-bromo-2-phenyl-2-butenoic acid, which resulted from solvent attack on intermediate allylic cations. Furthermore, both 3-alkoxy-1-phenyl-1-propyne and 3-alkoxy-1-phenyl-1-propanone were formed except when reactions were performed in HFP; their formation involved decarboxylation and their total yield was 15-40%.