Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... The regioselective enolization of 4-substituted cyclopentene-1,3-diones 3a-e is investigated under basic and acidic conditions. Enols 1 and enolethers 6, 7 are formed with the simultaneous endocyclic double bond migration in the side chain. ... Derivatives of 4-substituted 3- ...