Lf. Ma et D. Dolphin, MICHAEL-TYPE ADDITION OF 1,8-DIAZABICYCLO[5.4.0]UNDEC-7-ENE TO DIMETHYL ACETYLENEDICARBOXYLATE, Journal of the Chemical Society, Chemical Communications, (22), 1995, pp. 2251-2252
Michael reaction of DBU 1 with dimethyl acetylenedicarboxylate 2 and s
ubsequent intramolecular condensation of the adduct gives a tricyclic
derivative 6; a mechanism for the formation of 6 is proposed and an X-
ray crystal structure of 6: is presented.