Tetrahedron

Chemoselective protection of heteroaromatic aldehydes as imidazolidine derivatives: Preparation of 5-substituted furan-and thiophene-2-carboxaldehydes via metallo …

AJ Carpenter, DJ Chadwick

Index: Carpenter, Andrew J,; Chadwick, Derek J. Tetrahedron, 1985 , vol. 41, # 18 p. 3803 - 3812

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Citation Number: 46

Abstract

Furan-, thiophene-and N-methylpyrrole-2-carboxaldehydes may be transformed into the corresponding N, N'-dimethylimidazolidines in a reaction not requiring acid catalysis. The resulting furan and thiophene (but not N-methylpyrrole) derivatives may be metallated in high yields [predominantly at the 5 (α-) positions of the heteroaromatic rings] and the carboxaldehyde functionality regenerated under very mild conditions. Treatment of the ...