Study on the reactions of acetylenic aldehydes with dimethyl phosphite in basic media: Phosphonate-phosphate rearrangement versus 5-exo-dig cyclization reactions

Abstract

Tandem reactions of various acetylenic aldehydes with dimethyl phosphite in basic media were investigated. It was shown that in the case of a non-activated triple bond of the starting materials, the well-known Pudovik reaction followed by a subsequent phosphonate-phosphate rearrangement took place. On the other hand when the triple bond of the starting materials is activated by electron-withdrawing heterocycles, a smooth and regioselective tandem 5-exo-dig cyclization reactions becomes possible. © 2012 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim.