Synthesis of [2.2.3]Cyclazines, Aza[2.2.3]cyclazines and Their Related Compounds

Recent developments in the synthesis of L2.2.31cyclazines, benzo[gl[2.2.3lcyclazines, benzo[al[2.2.3lcyclazines, dibenzo[a.hl[2.2.3lcyc1azines, dibenzo[a,g1[2.2.31cyclazines, 1-aza[2.2.31cyclazines.5-azal2.2.3lcyclazines, and 1-azabenzo[hl[2.2.31cyclazines by the 18 + 21 cycloaddition reaction of dimethyl acetylenedicarboxylate IDMAD) with the various type indolizines a r e summarized by major emphasis that is placed on the results obtained in our own laboratory.The synthesis of indolizines, imidazo[l,2-alpyridine, and their related compounds which are key intermediates for the synthesis of cyclazines is also described.