Abstract Lithium perchlorate and acetic anhydride were the key additives for the multi- component reaction between 3-aminocyclohex-2-enones, formaldehyde, and malonates yielding adducts that were annulated under acidic conditions to afford bicyclic 2, 5-
[Keyser, Jean-Luc De; Cock, Christian J. C. De; Poupaert, Jacques H.; Dumont, Pierre Journal of Organic Chemistry, 1988 , vol. 53, # 20 p. 4859 - 4862]