A. Carpenter, D. Chadwick
1985
Citations
0
Influential Citations
36
Citations
Journal
Tetrahedron
Abstract
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 aldehydoketone 2-acetyl-5-formylthiophene with N , N '-dimethylethylenediamine gives only the product of reaction at the aldehyde function thus establishing this methodology as a potentially valuable method for the protection of an aldehyde in the presence of a ketone.