Controlling chemoselectivity—application of DMF di-t-butyl acetal in the regioselective synthesis of 3-monosubstituted indolizines
摘要:
Among a number of DMF dialkyl acetals investigated for the regioselective synthesis of 3-acylindolizines, the di-t-butyl acetal, via its iminium intermediate readily formed in situ, provides the highest chemoselectivity for the intermolecular cyclization of picolinium salts. DMF di-i-butyl acetal was applied to the syntheses of a variety of 3-acylated indolizines including alkyl, aryl, and heteroaryl substituents. (c) 2006 Elsevier Ltd. All rights reserved.