THROUGH-SPACE ELECTROSTATIC CONTROL IN A NOVEL REGIOSPECIFIC RING TRANSFORMATION OF 1,3,4-TRISUBSTITUTED MALEIMIDES

Article abstract of DOI:10.1016/S0040-4020(01)92096-4

Ring transformation of 1-ethoxycarbonyl-3,4-disubstituted maleimide in alkaline solution yielded exclusively 1,5-disubstituted orotic acid.No hydantoin derivatives were detected.These findings can be best explained by assuming that the initial attack of the hydroxylate anion occurs at C2 and not at C5.X-ray diffraction and quantum chemical investigation indicate that stereospecificity is mainly due to through-space electrostatic effects.