Conformational and stereoelectronic control in ring-transformations of<i>cis</i>-4,5-dialkoxytetrahydropurine-2,6,8-triones
作者:Nevenka Poje、Antun Palković、Mirko Poje
DOI:10.1002/jhet.5570340220
日期:1997.3
transamidation 5 → 4 presumably occurs via a bicyclic acid aminal type intermediate 3, heretofore misassigned as the reaction product. A curious base-catalysed rearrangement was encountered with the 5 (R1 = R3 = Me, R7 = H) cases, which afforded 5-methoxy-1,5-bis(methylaminocarbonyl)hydantoins 7. Remarkable stability of the conformationally rigid propellane type 4,5-ethylenedioxytetrahydropurine-2,6,8-triones