Abstract
| - A new synthesis of thepyrrolo[1,2-a]pyrazine system from pyrrole isdescribed. In light of the abinitio calculations carried out on this heterocyclic system someof its basic chemistry was investigatedand included electrophilic substitution, addition of organolithiumreagents, metalation with lithiumdiisopropylamide and subsequent reaction with electrophiles, andformation of salts by quaternization of the nonbridgehead nitrogen. N-ylides obtained fromthese salts undergo 1,3-dipolarcycloaddition with suitable dipolarophiles to givedipyrrolo[1,2-a]pyrazines,pyrazolo[1,5-a]-pyrrolo[2,1-c]pyrazines, and heterobetaines. Examples ofintramolecular 1,3-dipolar cycloadditions arealso reported.
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