Base catalysed rearrangements involving ylide intermediates. Part 11. Rearrangements of 3-phenylprop-2-ynylammonium ylides
作者:Sivapathasuntharam Mageswaran、W. David Ollis、Dolores A. Southam、Ian O. Sutherland、Yodhathai Thebtaranonth
DOI:10.1039/p19810001969
日期:——
novel [1,3] rearrangementinvolving the migration of a dimethylamino-group. The basecatalysedrearrangements of the bicyclic propynylammonium salts (52) and (56) do not show the inhibition expected for concerted [3,2] sigmatropic rearrangements in such bicyclic systems. This observation provides further evidence for a two-stage mechanism for the apparent [3,2] sigmatropic rearrangement of propynylammonium
Intramolecular 1,5-Hydride Shift in Products of Stevens 3,2-Rearrangement of Ammonium Salts Containing 3-Phenyl-2-propynyl Group
作者:A. V. Babakhanyan、V. S. Ovsepyan、S. T. Kocharyan、G. A. Panosyan
DOI:10.1023/b:rujo.0000003157.80528.0a
日期:2003.6
In products of Stevens 3,2-rearrangement of ammonium salts containing alongside alkoxycarbony-ymethyl also 3-phenyl-2-propynyl group an intramolecular 1,5-hydride shift is observed resulting in immonium salts which transform into antinoesters of enamine structure. The hydrolysis of the latter provides the lower aliphatic aldehydes and the corresponding aminoesters. An acid treatment of the reaction mixture affords a mixture of hydrogenated and nonhydrogenated esters of alpha-ketoacids originating from the mixture of 1,3-diene antinoesters. At treating, with concn. HCl of the obtained mixture the nonhydrogeneted ketoester undergoes cyclization into 4-methyl-3-phenyl-2-buten-1,4-olide.