gem-Dialkoxylation of 2-Acetylthiophenes and 2-Acetylfurans.

Reaction of 2-acetyl-substituted thiophenes and furans with alkyl nitrites in the presence of the corresponding aliphatic alcohols and hydrochloric acid leads to the formation of linear acetals of thienyl- and furylglyoxals, whose structure was established by IR, UV, NMR spectroscopy, and mass spectrometry methods. The main paths of the dissociation of the molecules under electron impact were established.