K. Matsumoto et al., SYNTHESIS OF 2,3,4-TRIPHENYL-3-AZABICYCLO[3.2.0]HEPTA-1,4-DIENE AND ITS NOVEL REACTION WITH DIMETHYL ACETYLENEDICARBOXYLATE, Journal of the Chemical Society. Perkin transactions. I, (18), 1997, pp. 2691-2693
A 3-azabicyclo[3.2.0]hepta-1,4-diene that is unsubstituted in the cycl
obutene moiety has been prepared for the first time and undergoes a no
vel reaction with dimethyl acetylenedicarboxylate to give azepine 6.