N,N-dimethylhydrazones,e.g., CH2:CFCH:NNMe2, prepd. from 2-fluoro-2-alkenals undergo smooth [4 + 2] cycloaddn. reactions with Me acrylate, di-Me acetylenedicarboxylates and quinones. The resulting 3-fluoropyridines, e.g., I, or dihydro and tetrahydro deriv ...
1994