Malodinitrile derivative

An acid-resistant protecting principle for carbonyl groups consists of the a,a-dicyanoethylene derivatives (96). They are obtained from carbonyl compounds, e.g. pyrrole aldehydes (95), by Knoevenagel condensation with malodinitrile. In general, mineral acids and Lewis acids, which are used in Friedel-... 

Derivatives of the type 29 have also proved to be more suitable starting materials than the corresponding 0-analog for condensation reactions with carbanions like malodinitrile, ultimately enabling the formal replacement of O by... 

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