摘要:
A double acceptor-activated cycloalkene 1 reacts in an FeCl3 . 6 H2O catalysed Michael reaction surprisingly as a donor. The constitution of the product 2 results from a reaction of 1 in the gamma-position, thus the Michael reaction is vinylogous with respect to the donor. A tautomerism between the enone 1 and the dienol 4 is found to be a precondition for this reactivity.