Cyanoselenation ketene 0,0-acetals

Orthoesters react with hydrocyanic acid, catalyzed by ZnCh, to give 2,2-dialkoxycarbonitriles (424 equation 201)." These nitriles can also be obtained by treatment of orthoesters with acyl cyanides" or trimethylsilyl cyanide in the presence of Lewis acids (BF3, SnCh)." Cyanoselenation of ketene 0,0-acetals affords the nitriles (425 Scheme 77)," " from which other compounds of this type can be prepared, e.g. (426) and (427), by splitting off the phenylselenyl group. The acetonitrile derivative (428 equation 202) is a byproduct (23%) in the photochemical cycloaddition of ketene diethylacetal to 6-cyanouracil." ... 

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